This document provides an overview of chemical bonding concepts including ionic bonds, covalent bonds, and metallic bonds. It discusses how ionic bonds form via the transfer of electrons between metals and nonmetals to form oppositely charged ions. Covalent bonds are described as the sharing of electrons between nonmetals. Metallic bonding is explained as a "sea of electrons" that holds positively charged metal ions in a lattice structure. The properties of ionic compounds, covalent compounds, and metals are contrasted. Examples of giant covalent structures like diamond and graphite are analyzed in terms of their bonding and properties. Learning outcomes are stated throughout to guide the reader.
This document discusses periodic trends in elements across periods and down groups in the periodic table. It explains that elements in the same group have the same number of valence electrons and thus similar chemical properties, while periods are related to the number of electron shells. Metals are on the left side of the table and become more nonmetallic from left to right across periods as atomic number increases.
The document outlines key concepts in electrochemistry including:
1. Electrolysis involves using electricity to break down ionic compounds or solutions into their components. It occurs when ions are able to move freely in molten or aqueous states.
2. During electrolysis, cations move to the cathode where they gain electrons and undergo reduction reactions. Anions move to the anode where they lose electrons and undergo oxidation reactions.
3. The electrolysis of molten ionic compounds produces metals at the cathode and non-metals at the anode. Electrolysis of aqueous solutions can produce hydrogen and oxygen from water or discharge other ions depending on their reactivity.
The document outlines key concepts about atomic structure including the structure of atoms with protons, neutrons and electrons, atomic number and mass number, electron configuration, isotopes, ions, and molecules of elements and compounds. It also provides learning outcomes for describing atomic structure and properties as well as interpreting atomic symbols and notations.
The document discusses different types of chemical bonds and macromolecular structures. It explains that ionic bonds form between metals and non-metals via the transfer of electrons, giving ionic compounds high melting points and the ability to conduct electricity when molten or dissolved. Covalent bonds form between non-metals by the sharing of electrons, resulting in covalent compounds having low melting points and the inability to conduct electricity. Some covalent substances exist as macromolecules or giant molecular structures like diamond and graphite. These have very high melting points and different properties compared to simple molecules. Metallic bonding is also described, involving positive metal ions in a "sea of electrons" giving metals properties like malleability and high conductivity
1. The document discusses different types of chemical bonding including ionic bonding, covalent bonding, and metallic bonding.
2. Ionic bonding involves the transfer of electrons between atoms to form ions with opposite charges that are attracted in a giant lattice structure.
3. Covalent bonding can form either simple molecules held together by shared electron pairs or giant covalent structures with thousands of atoms bonded together.
The document discusses the properties of two groups of elements - Group 18 noble gases and Group 1 alkali metals.
Group 18 consists of helium, neon, argon, krypton, xenon, and oganesson. Noble gases have full outer electron shells, making them chemically inert. Their melting and boiling points increase down the group as atomic size increases and van der Waals forces strengthen.
Group 1 includes lithium, sodium, potassium, cesium, and francium. Alkali metals react by losing one electron to form stable ions. Reactivity increases down the group as the valence electron is more loosely held. They react with water to form hydroxides and oxygen to form ox
The document discusses the electron configuration of potassium, which has 19 electrons arranged in shells with the inner shell containing 2 electrons, the next shell containing 8 electrons, the next shell containing 8 electrons, and the outer shell containing the remaining 1 electron. It also discusses periodic trends such as elements in the same group having similar properties and how additional electron shells are added as you move down periods of the periodic table.
The document outlines key learning outcomes and concepts about atomic structure, including describing the structure of atoms with atomic numbers 1 to 20, defining terms like atomic number and mass number, explaining electron configuration and outer electrons, and distinguishing between isotopes, ions, and molecules of elements and compounds. It also provides illustrations of atomic structure and examples of applying atomic structure concepts.
This document discusses periodic trends in elements across periods and down groups in the periodic table. It explains that elements in the same group have the same number of valence electrons and thus similar chemical properties, while periods are related to the number of electron shells. Metals are on the left side of the table and become more nonmetallic from left to right across periods as atomic number increases.
The document outlines key concepts in electrochemistry including:
1. Electrolysis involves using electricity to break down ionic compounds or solutions into their components. It occurs when ions are able to move freely in molten or aqueous states.
2. During electrolysis, cations move to the cathode where they gain electrons and undergo reduction reactions. Anions move to the anode where they lose electrons and undergo oxidation reactions.
3. The electrolysis of molten ionic compounds produces metals at the cathode and non-metals at the anode. Electrolysis of aqueous solutions can produce hydrogen and oxygen from water or discharge other ions depending on their reactivity.
The document outlines key concepts about atomic structure including the structure of atoms with protons, neutrons and electrons, atomic number and mass number, electron configuration, isotopes, ions, and molecules of elements and compounds. It also provides learning outcomes for describing atomic structure and properties as well as interpreting atomic symbols and notations.
The document discusses different types of chemical bonds and macromolecular structures. It explains that ionic bonds form between metals and non-metals via the transfer of electrons, giving ionic compounds high melting points and the ability to conduct electricity when molten or dissolved. Covalent bonds form between non-metals by the sharing of electrons, resulting in covalent compounds having low melting points and the inability to conduct electricity. Some covalent substances exist as macromolecules or giant molecular structures like diamond and graphite. These have very high melting points and different properties compared to simple molecules. Metallic bonding is also described, involving positive metal ions in a "sea of electrons" giving metals properties like malleability and high conductivity
1. The document discusses different types of chemical bonding including ionic bonding, covalent bonding, and metallic bonding.
2. Ionic bonding involves the transfer of electrons between atoms to form ions with opposite charges that are attracted in a giant lattice structure.
3. Covalent bonding can form either simple molecules held together by shared electron pairs or giant covalent structures with thousands of atoms bonded together.
The document discusses the properties of two groups of elements - Group 18 noble gases and Group 1 alkali metals.
Group 18 consists of helium, neon, argon, krypton, xenon, and oganesson. Noble gases have full outer electron shells, making them chemically inert. Their melting and boiling points increase down the group as atomic size increases and van der Waals forces strengthen.
Group 1 includes lithium, sodium, potassium, cesium, and francium. Alkali metals react by losing one electron to form stable ions. Reactivity increases down the group as the valence electron is more loosely held. They react with water to form hydroxides and oxygen to form ox
The document discusses the electron configuration of potassium, which has 19 electrons arranged in shells with the inner shell containing 2 electrons, the next shell containing 8 electrons, the next shell containing 8 electrons, and the outer shell containing the remaining 1 electron. It also discusses periodic trends such as elements in the same group having similar properties and how additional electron shells are added as you move down periods of the periodic table.
The document outlines key learning outcomes and concepts about atomic structure, including describing the structure of atoms with atomic numbers 1 to 20, defining terms like atomic number and mass number, explaining electron configuration and outer electrons, and distinguishing between isotopes, ions, and molecules of elements and compounds. It also provides illustrations of atomic structure and examples of applying atomic structure concepts.
This chapter discusses the periodic table, explaining that elements are arranged in order of atomic number and grouped into periods and groups based on their electron configuration, with groups having similar properties and periods showing trends down the table. Properties of elements in groups I, VII, and 0 are described, including their physical states, reactivity, and chemical properties.
The document provides information on elements and compounds. It defines an element as a substance that cannot be broken down further by chemical means, while a compound is made up of two or more elements chemically bonded together. Elements are the fundamental building blocks and are made of only one type of atom. Compounds have molecules made of two or more atom types. The document explains how to write chemical formulas and balanced equations to represent elements, compounds and chemical reactions.
The document discusses the periodic table of elements, explaining how the elements are organized according to properties like atomic number and mass and describing important groups of elements including metals, non-metals, noble gases, and families like alkali metals and halogens. It provides details on the development of the periodic table and key aspects of classifying and understanding the elements.
The document provides information on the structure of atoms, ionic and covalent bonding, the periodic table, properties of metals and non-metals, and chemical reactions. It discusses how atoms are composed of protons, neutrons and electrons, and how electrons are arranged in shells. It also explains how ionic bonding occurs through transfer of electrons between metals and non-metals, while covalent bonding involves sharing of electrons between non-metals.
This document discusses the properties and reactivity of metals. It begins by describing the physical properties of metals, such as their hardness, malleability and conductivity. It then discusses the chemical properties of metals, including how they form positive ions and react with oxygen, water and acids. The document introduces metal alloys and explains why they are stronger than pure metals. It also defines the reactivity series and uses it to predict and describe the reactions of different metals. The document discusses the reactions of various metal compounds and how the position of metals in the reactivity series affects their reactivity and the stability of their compounds.
This document provides an overview of key concepts in chemistry including:
1) The structure of atoms including protons, neutrons, and electrons. It also discusses isotopes and electron configuration.
2) The periodic table is introduced including periodic trends in properties and how elements are arranged in groups and periods. Metals, nonmetals, and chemical properties are also covered.
3) Bonding including ionic bonding between metals and nonmetals and covalent bonding between nonmetals is explained through examples like sodium chloride and water. Dot and cross diagrams are used to represent covalent bonds.
4) Compounds and chemical equations are discussed including balancing equations and calculating relative formula mass. Giant ionic structures
Ionic compounds are made up of positive metal ions and negative non-metal ions arranged in a crystal lattice. In ionic compounds like sodium chloride, the oppositely charged ions are held together by strong electrostatic forces of attraction. Potassium oxide and lithium oxide are examples where the metal ions (potassium and lithium) outnumber the oxygen ions in a ratio of about 1:2, as represented by their chemical formulas K2O and Li2O.
This document discusses matter and substances. It describes the kinetic theory of matter and states of matter. It explains that all matter is made up of atoms, which contain protons, electrons, and neutrons. The periodic table arranges elements based on proton number and displays their properties. Substances can be made of atoms, molecules, or ions, which determines their physical properties like melting point and electrical conductivity. Metals have properties like shine, malleability, and conductivity, while non-metals have dull surfaces and are brittle. Purification methods like filtration, crystallization, and distillation are used to obtain pure substances. Substances are important in daily life, and their properties allow them to be processed for different uses.
1) Noble gases are unreactive because their outer electron shells are full, giving them a stable configuration.
2) Atoms form ions to achieve a full outer shell like noble gases. Metals form cations by losing electrons, and non-metals form anions by gaining electrons.
3) Ionic bonds form when oppositely charged ions are attracted to each other, such as sodium and chloride ions forming sodium chloride. The chemical formula shows the ratio of ions.
This document discusses chemical bonding and intramolecular bonding. It begins by introducing ionic and covalent bonds as the two major types of intramolecular bonding that hold atoms together to form molecules. Ionic bonds form between ions through the transfer of electrons from metals to nonmetals. Covalent bonds form between nonmetals by the sharing of electrons. The document then goes into further detail about the formation of ions, ionic compounds through electron transfers, and the naming of ionic compounds according to IUPAC nomenclature rules.
Ionic bonding results from the electrostatic attraction between oppositely charged ions. When a metal atom reacts with a nonmetal, the metal typically loses electrons to form a cation while the nonmetal gains electrons to form an anion. These oppositely charged ions are then attracted to each other, forming an ionic bond. Ionic compounds have crystalline structures where the ions are arranged in repeating patterns. Their strong ionic bonds make them brittle with high melting points. Many ionic compounds dissolve in water to form electrolyte solutions where the ions are free to move.
This document provides an overview of transition elements and their properties including:
1) Transition elements have variable oxidation states due to their similar energy 4s and 3d electron levels. They can gain or lose electrons to form stable ions.
2) Transition elements form colored complexes when surrounded by ligands via coordinate bonding. Ligand exchange reactions can replace one ligand for another.
3) The shapes and colors of transition metal complexes are determined by the ligands present and the splitting of d orbitals. Different ligands cause different color changes through electron movement between d orbitals.
The document summarizes key aspects of the periodic table, including:
1) It describes the historical development of the periodic table by scientists like Lavoisier, Dobereiner, Newlands, Meyer, and Mendeleev.
2) It explains the modern arrangement of elements in the periodic table based on proton number and discusses the properties of elements in the same group and period.
3) It provides examples of properties and reactions of representative elements from groups 1, 17, 18 and period 3 of the periodic table. Transition elements and semimetals are also discussed.
This document discusses radicals, ions, and how to write chemical formulas. Radicals are species with unpaired electrons that can exist independently, and there are two main types - acid and basic radicals. Ions are charged species formed when atoms gain or lose electrons to become cations (positively charged) or anions (negatively charged). To write a chemical formula, you need the symbols of the elements and their valencies (combining capacities), then cross-multiply the valencies to get the formula. Examples of common cation and anion symbols and their valencies are provided.
Chemistry zimsec chapter 9 chemical periodicityalproelearning
This document summarizes key concepts about chemical periodicity, including the various blocks and periods in the periodic table. It describes trends in atomic properties like atomic radius, ionization energy, and electronegativity across periods and down groups. These trends are explained by factors like nuclear charge, atomic size, and shielding effects. Common reactions of representative elements like formation of oxides and chlorides from the third period are presented, along with equations. Structures and bonding of these compounds are discussed as well as their reactions with water.
The document discusses topics related to chemical reactions and the periodic table. It provides information on:
- Mendeleev's creation of the periodic table and how he arranged elements based on their properties.
- The structure of atoms consisting of protons, neutrons, and electrons located in electron shells around the nucleus.
- The modern periodic table including atomic number and mass number.
- Ionic bonding forming between metals and non-metals through the transfer of electrons. Ionic compounds have high melting/boiling points and conduct electricity when molten or dissolved.
- Covalent bonding forming when atoms share electrons in covalent molecules. Simple covalent substances have low melting/boiling points while giant
This document discusses physical and chemical changes, heat changes in chemical reactions, the reactivity of metals, electrolysis, and the production of electrical energy from chemical reactions. It defines physical and chemical changes, compares their characteristics, and provides examples of each. It describes how chemical reactions can be exothermic or endothermic and releases or absorbs heat. It also discusses the reactivity series of metals and how the position of a metal determines its reactions with water, acids, oxygen, and in extractions. Electrolysis and its uses in metal extraction and plating are explained. Finally, it covers simple cells and different battery types.
The document discusses the history and modern understanding of the periodic table. It covers how elements are arranged based on proton number and how this explains trends in properties within groups. Specific groups like alkali metals, halogens, and transition metals are examined in terms of their structures, properties, and reactions. Common acid-base reactions and quantitative chemical calculations are also summarized.
The document provides information on several chemistry concepts and experiments. It includes:
1) A chapter on matter that discusses states of matter, kinetic theory, and heating curves.
2) Chapters on chemical formulas, periodic table, chemical bonds, and electrochemistry.
3) An experiment on determining the end point of a neutralization reaction between potassium hydroxide and hydrochloric acid.
This document provides a summary of key chemistry concepts covered on the Regents exam, including:
1) Elements cannot be broken down chemically, while mixtures contain two or more physically combined elements or substances.
2) Chemical changes result in new substances with different properties, while physical changes do not alter the identity of the substance.
3) Gas laws relate the pressure, volume, temperature, and amount of gas in chemical reactions and problems.
4) Atoms are made up of protons, neutrons, and electrons. The number of protons determines the element.
5) Chemical bonds, including ionic and covalent bonds, result from the transfer or sharing of electrons between atoms.
This document provides an overview of chemical bonding and macromolecular structures. It discusses the different types of bonds including ionic bonds formed by transfer of electrons between metals and non-metals, and covalent bonds formed by sharing of electrons between non-metals. Ionic compounds have high melting and boiling points and conduct electricity when molten or dissolved, while covalent compounds have low melting and boiling points and do not conduct electricity. It also describes macromolecular and metallic structures, noting that macromolecules have very high melting points due to their large size, while metals form lattice structures with positive ions in a sea of delocalized electrons, making them malleable.
This document discusses chemical bonding and macromolecular structures. It begins by explaining the different types of bonds - ionic bonds formed between metals and non-metals by electron transfer, and covalent bonds formed between non-metals by electron sharing. It describes the properties of ionic and covalent compounds. It then discusses macromolecular structures found in substances like diamond, graphite and metals. It explains metallic bonding and compares the structures and properties of diamond and graphite. In the end, it discusses the different uses of diamond and graphite based on their properties.
This chapter discusses the periodic table, explaining that elements are arranged in order of atomic number and grouped into periods and groups based on their electron configuration, with groups having similar properties and periods showing trends down the table. Properties of elements in groups I, VII, and 0 are described, including their physical states, reactivity, and chemical properties.
The document provides information on elements and compounds. It defines an element as a substance that cannot be broken down further by chemical means, while a compound is made up of two or more elements chemically bonded together. Elements are the fundamental building blocks and are made of only one type of atom. Compounds have molecules made of two or more atom types. The document explains how to write chemical formulas and balanced equations to represent elements, compounds and chemical reactions.
The document discusses the periodic table of elements, explaining how the elements are organized according to properties like atomic number and mass and describing important groups of elements including metals, non-metals, noble gases, and families like alkali metals and halogens. It provides details on the development of the periodic table and key aspects of classifying and understanding the elements.
The document provides information on the structure of atoms, ionic and covalent bonding, the periodic table, properties of metals and non-metals, and chemical reactions. It discusses how atoms are composed of protons, neutrons and electrons, and how electrons are arranged in shells. It also explains how ionic bonding occurs through transfer of electrons between metals and non-metals, while covalent bonding involves sharing of electrons between non-metals.
This document discusses the properties and reactivity of metals. It begins by describing the physical properties of metals, such as their hardness, malleability and conductivity. It then discusses the chemical properties of metals, including how they form positive ions and react with oxygen, water and acids. The document introduces metal alloys and explains why they are stronger than pure metals. It also defines the reactivity series and uses it to predict and describe the reactions of different metals. The document discusses the reactions of various metal compounds and how the position of metals in the reactivity series affects their reactivity and the stability of their compounds.
This document provides an overview of key concepts in chemistry including:
1) The structure of atoms including protons, neutrons, and electrons. It also discusses isotopes and electron configuration.
2) The periodic table is introduced including periodic trends in properties and how elements are arranged in groups and periods. Metals, nonmetals, and chemical properties are also covered.
3) Bonding including ionic bonding between metals and nonmetals and covalent bonding between nonmetals is explained through examples like sodium chloride and water. Dot and cross diagrams are used to represent covalent bonds.
4) Compounds and chemical equations are discussed including balancing equations and calculating relative formula mass. Giant ionic structures
Ionic compounds are made up of positive metal ions and negative non-metal ions arranged in a crystal lattice. In ionic compounds like sodium chloride, the oppositely charged ions are held together by strong electrostatic forces of attraction. Potassium oxide and lithium oxide are examples where the metal ions (potassium and lithium) outnumber the oxygen ions in a ratio of about 1:2, as represented by their chemical formulas K2O and Li2O.
This document discusses matter and substances. It describes the kinetic theory of matter and states of matter. It explains that all matter is made up of atoms, which contain protons, electrons, and neutrons. The periodic table arranges elements based on proton number and displays their properties. Substances can be made of atoms, molecules, or ions, which determines their physical properties like melting point and electrical conductivity. Metals have properties like shine, malleability, and conductivity, while non-metals have dull surfaces and are brittle. Purification methods like filtration, crystallization, and distillation are used to obtain pure substances. Substances are important in daily life, and their properties allow them to be processed for different uses.
1) Noble gases are unreactive because their outer electron shells are full, giving them a stable configuration.
2) Atoms form ions to achieve a full outer shell like noble gases. Metals form cations by losing electrons, and non-metals form anions by gaining electrons.
3) Ionic bonds form when oppositely charged ions are attracted to each other, such as sodium and chloride ions forming sodium chloride. The chemical formula shows the ratio of ions.
This document discusses chemical bonding and intramolecular bonding. It begins by introducing ionic and covalent bonds as the two major types of intramolecular bonding that hold atoms together to form molecules. Ionic bonds form between ions through the transfer of electrons from metals to nonmetals. Covalent bonds form between nonmetals by the sharing of electrons. The document then goes into further detail about the formation of ions, ionic compounds through electron transfers, and the naming of ionic compounds according to IUPAC nomenclature rules.
Ionic bonding results from the electrostatic attraction between oppositely charged ions. When a metal atom reacts with a nonmetal, the metal typically loses electrons to form a cation while the nonmetal gains electrons to form an anion. These oppositely charged ions are then attracted to each other, forming an ionic bond. Ionic compounds have crystalline structures where the ions are arranged in repeating patterns. Their strong ionic bonds make them brittle with high melting points. Many ionic compounds dissolve in water to form electrolyte solutions where the ions are free to move.
This document provides an overview of transition elements and their properties including:
1) Transition elements have variable oxidation states due to their similar energy 4s and 3d electron levels. They can gain or lose electrons to form stable ions.
2) Transition elements form colored complexes when surrounded by ligands via coordinate bonding. Ligand exchange reactions can replace one ligand for another.
3) The shapes and colors of transition metal complexes are determined by the ligands present and the splitting of d orbitals. Different ligands cause different color changes through electron movement between d orbitals.
The document summarizes key aspects of the periodic table, including:
1) It describes the historical development of the periodic table by scientists like Lavoisier, Dobereiner, Newlands, Meyer, and Mendeleev.
2) It explains the modern arrangement of elements in the periodic table based on proton number and discusses the properties of elements in the same group and period.
3) It provides examples of properties and reactions of representative elements from groups 1, 17, 18 and period 3 of the periodic table. Transition elements and semimetals are also discussed.
This document discusses radicals, ions, and how to write chemical formulas. Radicals are species with unpaired electrons that can exist independently, and there are two main types - acid and basic radicals. Ions are charged species formed when atoms gain or lose electrons to become cations (positively charged) or anions (negatively charged). To write a chemical formula, you need the symbols of the elements and their valencies (combining capacities), then cross-multiply the valencies to get the formula. Examples of common cation and anion symbols and their valencies are provided.
Chemistry zimsec chapter 9 chemical periodicityalproelearning
This document summarizes key concepts about chemical periodicity, including the various blocks and periods in the periodic table. It describes trends in atomic properties like atomic radius, ionization energy, and electronegativity across periods and down groups. These trends are explained by factors like nuclear charge, atomic size, and shielding effects. Common reactions of representative elements like formation of oxides and chlorides from the third period are presented, along with equations. Structures and bonding of these compounds are discussed as well as their reactions with water.
The document discusses topics related to chemical reactions and the periodic table. It provides information on:
- Mendeleev's creation of the periodic table and how he arranged elements based on their properties.
- The structure of atoms consisting of protons, neutrons, and electrons located in electron shells around the nucleus.
- The modern periodic table including atomic number and mass number.
- Ionic bonding forming between metals and non-metals through the transfer of electrons. Ionic compounds have high melting/boiling points and conduct electricity when molten or dissolved.
- Covalent bonding forming when atoms share electrons in covalent molecules. Simple covalent substances have low melting/boiling points while giant
This document discusses physical and chemical changes, heat changes in chemical reactions, the reactivity of metals, electrolysis, and the production of electrical energy from chemical reactions. It defines physical and chemical changes, compares their characteristics, and provides examples of each. It describes how chemical reactions can be exothermic or endothermic and releases or absorbs heat. It also discusses the reactivity series of metals and how the position of a metal determines its reactions with water, acids, oxygen, and in extractions. Electrolysis and its uses in metal extraction and plating are explained. Finally, it covers simple cells and different battery types.
The document discusses the history and modern understanding of the periodic table. It covers how elements are arranged based on proton number and how this explains trends in properties within groups. Specific groups like alkali metals, halogens, and transition metals are examined in terms of their structures, properties, and reactions. Common acid-base reactions and quantitative chemical calculations are also summarized.
The document provides information on several chemistry concepts and experiments. It includes:
1) A chapter on matter that discusses states of matter, kinetic theory, and heating curves.
2) Chapters on chemical formulas, periodic table, chemical bonds, and electrochemistry.
3) An experiment on determining the end point of a neutralization reaction between potassium hydroxide and hydrochloric acid.
This document provides a summary of key chemistry concepts covered on the Regents exam, including:
1) Elements cannot be broken down chemically, while mixtures contain two or more physically combined elements or substances.
2) Chemical changes result in new substances with different properties, while physical changes do not alter the identity of the substance.
3) Gas laws relate the pressure, volume, temperature, and amount of gas in chemical reactions and problems.
4) Atoms are made up of protons, neutrons, and electrons. The number of protons determines the element.
5) Chemical bonds, including ionic and covalent bonds, result from the transfer or sharing of electrons between atoms.
This document provides an overview of chemical bonding and macromolecular structures. It discusses the different types of bonds including ionic bonds formed by transfer of electrons between metals and non-metals, and covalent bonds formed by sharing of electrons between non-metals. Ionic compounds have high melting and boiling points and conduct electricity when molten or dissolved, while covalent compounds have low melting and boiling points and do not conduct electricity. It also describes macromolecular and metallic structures, noting that macromolecules have very high melting points due to their large size, while metals form lattice structures with positive ions in a sea of delocalized electrons, making them malleable.
This document discusses chemical bonding and macromolecular structures. It begins by explaining the different types of bonds - ionic bonds formed between metals and non-metals by electron transfer, and covalent bonds formed between non-metals by electron sharing. It describes the properties of ionic and covalent compounds. It then discusses macromolecular structures found in substances like diamond, graphite and metals. It explains metallic bonding and compares the structures and properties of diamond and graphite. In the end, it discusses the different uses of diamond and graphite based on their properties.
This document discusses chemical bonding and different types of bonds and structures. It explains that ionic bonds form between metals and non-metals via the transfer of electrons, giving ionic compounds high melting points and the ability to conduct electricity when molten or dissolved. Covalent bonds form between non-metals by the sharing of electrons, resulting in molecular compounds with low melting points that do not conduct electricity. It also describes macromolecular and metallic bonding, noting that structures like diamond, graphite and metals have high melting points due to their extended lattice structures held together by strong bonds or interactions between particles.
The document discusses chemical bonding, specifically ionic and covalent bonding. Ionic bonding involves the transfer of electrons between metals and non-metals to form ions that achieve stable noble gas electron configurations. Covalent bonding involves the sharing of electrons between non-metals. Both ionic and covalent bonds form when atoms attain noble gas electron configurations. Ionic compounds have characteristics like high melting points and conductivity when molten or dissolved, while covalent compounds have low melting points and are non-conductive.
The document discusses different types of chemical bonds including intramolecular and intermolecular forces. It defines ionic bonds as occurring between metal and non-metal atoms through the transfer of electrons, and covalent bonds as occurring between non-metal atoms through the sharing of electrons. The document also discusses metallic bonding, the octet rule, and provides examples of different ionic compounds.
I. Ionic compounds form when oppositely charged ions bond via ionic bonds. When atoms gain or lose electrons to achieve stable octet configurations, they form cations or anions that bond in a crystalline lattice.
II. Ionic bonds are strong electrostatic attractions between cations and anions. Ionic compounds have high melting and boiling points and are brittle solids that do not conduct electricity well.
III. Formulas and names of ionic compounds follow conventions where the cation is written first followed by the anion. Polyatomic ions are also considered when writing formulas and names.
Class 11 Chemistry Revision Notes Chemical Bonding and Molecular Structure.pdfNadishaFathima
This document discusses chemical bonding and molecular structure. It begins by introducing atoms, molecules, and the forces that hold atoms together in molecules. It then defines chemical bonding and describes the main types of bonds: ionic, covalent, hydrogen, and polar bonds. The remainder of the document discusses these bond types in more detail, including how to represent bonds using Lewis structures, the characteristics of ionic compounds, factors that influence ionic bond formation, and more. It also introduces concepts like formal charge, valence shell electron pair repulsion theory (VSEPR) for predicting molecular geometry, and hybridization.
Atoms form bonds to achieve stable electron configurations. Covalent bonds form when atoms share valence electrons to fill their outer shells. Different bonding structures lead to varied properties. Diamond has a giant covalent structure where each carbon atom bonds to four others in a 3D network, giving it properties like hardness. Graphite also contains carbon but its layers can slide due to weaker bonds between layers, making it soft.
The document discusses chemical bonding and different types of bonds that join atoms together to form compounds. It begins by explaining that atoms combine to attain stable noble gas configurations, often through gaining or losing electrons to achieve 8 electrons in their outer shell.
It then describes ionic bonding specifically, where atoms transfer electrons to attain stable configurations. Sodium loses an electron to form Na+ while chlorine gains an electron to form Cl-, and the oppositely charged ions are held together by electrostatic attraction to form NaCl. Ionic compounds have high melting points, conduct electricity when molten or dissolved, and are generally soluble in water but not organic solvents.
The document also provides examples of other ionic compounds formed by electron
Investigation Of The Thermal Decomposition Of Copper...Alexis Naranjo
This molecular dynamics simulation examines the indentation response of an aluminum-amorphous silicon core-shell nanostructure. The study investigates the deformation behavior of the amorphous silicon shell and aluminum core under spherical indentation. It also explores how the density of the amorphous silicon, indenter radius size, and core/shell ratio size affect the structural deformation of the nanostructure. The simulation aims to provide insights into optimizing the properties of core-shell nanostructures for applications.
Ionic compounds are formed when ions bond via ionic bonds. Ions form when atoms gain or lose electrons to achieve a stable electron configuration. Ionic bonds result from the electrostatic attraction between oppositely charged ions. Ionic compounds consist of a crystal lattice structure where ions are arranged in a repeating pattern. Metals form metallic bonds where delocalized electrons are attracted to metallic cations. Alloys are mixtures of metals or metals with other elements that have distinct properties from their components.
- Organic chemistry involves carbon-based compounds, with hydrogen usually being the second most common element. Other common elements are oxygen, nitrogen, sulfur, and halogens.
- Most bonds in organic compounds are covalent, formed through shared electron pairs between atoms. Whether bonds are ionic or covalent depends on the electro-negativity difference between bonded atoms.
- Polar covalent bonds form when there is some electro-negativity difference between atoms, causing the electron cloud to shift slightly towards the more electronegative atom. This gives the atoms partial positive or negative charges.
This document provides instructions for navigating a presentation on chemical bonding. It describes how to view the presentation as a slideshow, advance through slides, access resources and lessons, and exit the slideshow. The presentation covers topics like electrons and chemical bonding, ionic bonds, and covalent and metallic bonds. It includes bellringer questions, learning objectives, content on topics like ion formation and crystal lattices, and a concept map to summarize the key topics.
This document provides instructions for navigating a presentation on chemical bonding. It describes how to view the presentation as a slideshow, advance through slides, access resources and lessons, and exit the slideshow. The presentation contains sections on electrons and chemical bonding, ionic bonds, and covalent and metallic bonds. It includes objectives, content on topics like valence electrons and ionic compounds, and assessment questions.
This document provides information on ionic compounds and metals. It discusses how ions are formed through the gain or loss of valence electrons to achieve stable octet configurations. Ionic compounds contain oppositely charged ions that are attracted to each other. Their crystal lattices give them high melting and boiling points. Metals form lattices with cations surrounded by a sea of delocalized electrons, giving them malleability, ductility, and high conductivity.
Ionic bonds form when oppositely charged ions attract each other, forming ionic compounds. Cations form when atoms lose electrons to achieve a stable electron configuration, while anions form when atoms gain electrons. Ionic compounds consist of a crystal lattice structure where cations are surrounded by anions. They have properties like high melting points and boiling points since energy is required to overcome the strong electrostatic attractions between ions.
The document discusses chemical bonds and the formation of compounds from atoms. It begins by describing how the atoms in vitamin C bond together in a very specific orientation to form the molecule's shape. It then provides an outline of the chapter sections, which include topics like periodic trends in atomic properties, Lewis structures of atoms and compounds, and molecular shape. The chapter examines various types of bonds like ionic bonds formed through the transfer of electrons between atoms and covalent bonds formed by the sharing of electrons between atoms. It discusses concepts such as electronegativity and how molecular shape is influenced by bond polarity.
Ionic compounds form when oppositely charged ions attract each other, forming ionic bonds. Ions are formed when atoms gain or lose valence electrons to achieve a stable electron configuration. In ionic compounds, the cation is written first followed by the anion in chemical formulas. Metals form metallic bonds where metal atoms donate their valence electrons, which are free to move throughout the crystal lattice structure.
Chemical bonding xi , dr.mona srivastava , founder masterchemclassesDR MONA Srivastava
Viewers,
This ppt of chemical bonding is designed to give a complete idea and though conceptual extract of the topic for the students of XI to help them understand the basics of chemical bonding in chemistry. Hope it covers all important aspects and points .
Dr Mona Srivastava
Founder-
Masterchemclasses
According to Gilbert Lewis, atoms combine i order to achieve a more stable electron configuration. Maximum stability is obtained when an atom is isoelectronic with a noble gas. This presentation would enable students to relate lattice energy with physical properties such as melting point.
The document provides examples of algorithms using different loop structures. It includes an example of an if/else conditional statement to determine if a student passed an exam based on a 55 point pass mark. It also gives examples of a for loop to read and print a price list of 10 items, a while loop to continuously prompt a user for input until they enter 0, and a repeat loop to also continuously prompt for input until 0 is entered and print each number.
Variables are containers that store and hold values that can be manipulated during a program's execution. They are usually stored in RAM and can be modified. Constants also store values but cannot be modified during execution and are stored in ROM. It is important to choose clear, meaningful names for variables and constants that disclose what they represent. Common variable data types include integers, floating point numbers, characters, Booleans, and strings.
The document provides examples of algorithms using different loop structures. It includes an example of an if/else conditional statement to determine if a student passed an exam based on a 55 point pass mark. It also gives examples of a for loop to read and print a price list of 10 items, a while loop to continuously prompt a user for input until they enter 0, and a repeat loop to also continuously prompt for input until 0 is entered and print each number.
1) Volumetric analysis involves titrating a solution of known concentration against an unknown solution to determine the concentration of the unknown.
2) The document discusses key steps in volumetric analysis including using a pipette to accurately measure a fixed volume of the unknown solution, and a burette to slowly add and measure the titrating solution.
3) Indicators are used to signal the endpoint of the titration reaction, and multiple titrations should be carried out to obtain consistent results. The concentration of the unknown can then be calculated using the titration data and balanced chemical equation.
This document discusses relative atomic mass and relative molecular mass. It defines these terms and explains how they are calculated by comparing the mass of an atom or molecule to 1/12 the mass of one carbon-12 atom. The key points covered are:
- Relative atomic mass is the average mass of an atom of an element compared to 1/12 the mass of one carbon-12 atom.
- Relative molecular mass is the average mass of a molecule compared to 1/12 the mass of one carbon-12 atom. It is calculated by adding the relative atomic masses of the atoms in the molecule.
- Examples are provided to demonstrate calculating relative atomic masses from the periodic table and relative molecular masses by adding atomic masses
This document provides information about qualitative analysis, including identifying gases, cations, and anions in an unknown sample through a series of tests. It outlines the key steps in qualitative analysis: making preliminary observations of the sample, carrying out tests in a specific order, recording observations, drawing conclusions, and identifying the unknown substance. It also provides tables of solubility rules, expected observations for common gas tests and reactions with reagents to identify cations and anions. The goal of qualitative analysis is to use systematic testing to determine the components present in an unknown substance.
The document describes non-metals and their properties. It discusses key non-metals like hydrogen, oxygen, nitrogen, carbon, chlorine and sulfur. It explains that non-metals have higher electronegativity and are generally poor conductors of heat and electricity. The document also outlines several industrial processes for producing important non-metal compounds like chlorine, sulfuric acid and ammonia.
The document discusses enthalpy changes and exothermic and endothermic reactions. It defines exothermic reactions as reactions where heat energy is released to the surroundings, giving a negative enthalpy change. Endothermic reactions absorb heat from the surroundings, having a positive enthalpy change. Bond breaking requires energy and is endothermic, while bond forming releases energy and is exothermic. Whether a reaction is exothermic or endothermic depends on if more energy is released or absorbed during bond breaking and forming.
This document provides an overview of polymers and includes definitions, examples, and properties. It begins by defining polymers as macromolecules made up of monomers linked together. It describes the two types of polymerization - addition and condensation. Examples of addition polymers include polyethene, PVC, and Teflon. Condensation polymers include nylon, polyesters, and proteins. The document also discusses the structure of polymers, properties, uses, and environmental impacts of plastics.
This document discusses fossil fuels and petroleum. It identifies natural gas and petroleum as natural sources of hydrocarbons. It lists the main uses of at least three fractions obtained from fractional distillation of petroleum. It also describes cracking of petroleum fractions, which is the process of breaking large petroleum molecules into smaller molecules using heat and catalysts, in order to produce more useful lighter fractions.
The document outlines learning outcomes and content about hydrocarbons. It discusses the bonding ability of carbon and classification of organic compounds. It then focuses on the homologous series, structures, properties and reactions of two types of hydrocarbons - alkanes and alkenes. For alkanes, it describes the alkane homologous series, structures of alkanes, and their combustion and substitution reactions with halogens. For alkenes, it covers similar topics including their unsaturated nature and addition reactions with halogens.
This document discusses reaction rates and factors that affect reaction rates. It begins by explaining what reaction rate means and how it can be measured by determining the amount of product formed, reactant used, or time taken for a reaction to complete. It then discusses several factors that affect reaction rates, including temperature, concentration, particle size, catalysts, and pressure. Higher temperatures, concentrations, smaller particle sizes, and presence of catalysts generally increase reaction rates by increasing the frequency and energy of collisions between reacting particles. The document also explains collision theory and how catalysts work by lowering activation energy or increasing surface area of reactants. Real-world examples of reaction rates and catalyst uses are provided.
The document outlines key concepts in electrochemistry including:
- Conductors and electrolytes allow electric currents through movement of charged particles. Electrolytes must be molten or dissolved.
- During electrolysis, cations move to the cathode and are reduced while anions move to the anode and are oxidized.
- Products depend on the electrolyte - molten salts produce metals at the cathode and nonmetals at the anode, while solutions can produce gases from water. Reactions follow selective discharge principles.
This document outlines key concepts about acids, bases, and salts. It defines acids as substances that produce hydrogen ions in water and discusses their properties, including reacting with metals and carbonates. Bases are defined as metal oxides or hydroxides, while alkalis are soluble bases. The document discusses the pH scale for measuring acidity and alkalinity. It also defines the four types of oxides and how salts are formed through neutralization reactions between acids and bases. Key terms like indicators, strong/weak acids, and methods of preparing salts are also summarized.
This document provides information about the mole concept in chemistry. It defines the mole as the amount of substance that contains as many elementary entities as there are atoms in 12 grams of carbon-12. It then discusses how to calculate the number of moles, mass of one mole of atoms or molecules, and molar mass. The document also explains how to derive empirical and molecular formulas from percentage composition data and relative molecular masses. It provides examples of calculating limiting reactants and the molar volume of gases.
This document provides an overview of chemical bonding and different types of bonds. It begins by explaining ionic bonds which are formed by the transfer of electrons between metals and non-metals. Sodium chloride is given as an example. Covalent bonds are then introduced and involve the sharing of electrons between non-metals like hydrogen and oxygen. The properties of ionic and covalent compounds are contrasted. Ionic compounds have high melting points and conduct electricity when molten or dissolved, while covalent compounds have lower melting points and do not conduct electricity. Metallic bonding is described involving positive metal ions in a "sea of electrons". Finally, macromolecular structures like diamond and graphite are discussed and how their different bonding structures
This document discusses mixtures and separation techniques. It defines pure substances and mixtures, and describes different types of mixtures like solutions, suspensions, and colloids. Several physical separation methods are described, including filtration, evaporation, crystallization, sublimation, distillation, fractional distillation, use of a separating funnel, and chromatography. These techniques separate mixtures based on differences in properties of the components like solubility, boiling point, and polarity. The document also provides examples to illustrate key concepts and separation processes.
This document discusses the three states of matter - solids, liquids, and gases. It explains that the state of a substance depends on temperature and pressure, and describes different phase changes like melting, boiling, freezing, and evaporation. It also compares the properties of the three states of matter and explains how particle motion and kinetic energy differences lead to changes between the states. The document provides examples to illustrate concepts like diffusion and discusses factors that influence the rate of diffusion.
How Barcodes Can Be Leveraged Within Odoo 17Celine George
In this presentation, we will explore how barcodes can be leveraged within Odoo 17 to streamline our manufacturing processes. We will cover the configuration steps, how to utilize barcodes in different manufacturing scenarios, and the overall benefits of implementing this technology.
Chapter wise All Notes of First year Basic Civil Engineering.pptxDenish Jangid
Chapter wise All Notes of First year Basic Civil Engineering
Syllabus
Chapter-1
Introduction to objective, scope and outcome the subject
Chapter 2
Introduction: Scope and Specialization of Civil Engineering, Role of civil Engineer in Society, Impact of infrastructural development on economy of country.
Chapter 3
Surveying: Object Principles & Types of Surveying; Site Plans, Plans & Maps; Scales & Unit of different Measurements.
Linear Measurements: Instruments used. Linear Measurement by Tape, Ranging out Survey Lines and overcoming Obstructions; Measurements on sloping ground; Tape corrections, conventional symbols. Angular Measurements: Instruments used; Introduction to Compass Surveying, Bearings and Longitude & Latitude of a Line, Introduction to total station.
Levelling: Instrument used Object of levelling, Methods of levelling in brief, and Contour maps.
Chapter 4
Buildings: Selection of site for Buildings, Layout of Building Plan, Types of buildings, Plinth area, carpet area, floor space index, Introduction to building byelaws, concept of sun light & ventilation. Components of Buildings & their functions, Basic concept of R.C.C., Introduction to types of foundation
Chapter 5
Transportation: Introduction to Transportation Engineering; Traffic and Road Safety: Types and Characteristics of Various Modes of Transportation; Various Road Traffic Signs, Causes of Accidents and Road Safety Measures.
Chapter 6
Environmental Engineering: Environmental Pollution, Environmental Acts and Regulations, Functional Concepts of Ecology, Basics of Species, Biodiversity, Ecosystem, Hydrological Cycle; Chemical Cycles: Carbon, Nitrogen & Phosphorus; Energy Flow in Ecosystems.
Water Pollution: Water Quality standards, Introduction to Treatment & Disposal of Waste Water. Reuse and Saving of Water, Rain Water Harvesting. Solid Waste Management: Classification of Solid Waste, Collection, Transportation and Disposal of Solid. Recycling of Solid Waste: Energy Recovery, Sanitary Landfill, On-Site Sanitation. Air & Noise Pollution: Primary and Secondary air pollutants, Harmful effects of Air Pollution, Control of Air Pollution. . Noise Pollution Harmful Effects of noise pollution, control of noise pollution, Global warming & Climate Change, Ozone depletion, Greenhouse effect
Text Books:
1. Palancharmy, Basic Civil Engineering, McGraw Hill publishers.
2. Satheesh Gopi, Basic Civil Engineering, Pearson Publishers.
3. Ketki Rangwala Dalal, Essentials of Civil Engineering, Charotar Publishing House.
4. BCP, Surveying volume 1
A Visual Guide to 1 Samuel | A Tale of Two HeartsSteve Thomason
These slides walk through the story of 1 Samuel. Samuel is the last judge of Israel. The people reject God and want a king. Saul is anointed as the first king, but he is not a good king. David, the shepherd boy is anointed and Saul is envious of him. David shows honor while Saul continues to self destruct.
Elevate Your Nonprofit's Online Presence_ A Guide to Effective SEO Strategies...TechSoup
Whether you're new to SEO or looking to refine your existing strategies, this webinar will provide you with actionable insights and practical tips to elevate your nonprofit's online presence.
THE SACRIFICE HOW PRO-PALESTINE PROTESTS STUDENTS ARE SACRIFICING TO CHANGE T...indexPub
The recent surge in pro-Palestine student activism has prompted significant responses from universities, ranging from negotiations and divestment commitments to increased transparency about investments in companies supporting the war on Gaza. This activism has led to the cessation of student encampments but also highlighted the substantial sacrifices made by students, including academic disruptions and personal risks. The primary drivers of these protests are poor university administration, lack of transparency, and inadequate communication between officials and students. This study examines the profound emotional, psychological, and professional impacts on students engaged in pro-Palestine protests, focusing on Generation Z's (Gen-Z) activism dynamics. This paper explores the significant sacrifices made by these students and even the professors supporting the pro-Palestine movement, with a focus on recent global movements. Through an in-depth analysis of printed and electronic media, the study examines the impacts of these sacrifices on the academic and personal lives of those involved. The paper highlights examples from various universities, demonstrating student activism's long-term and short-term effects, including disciplinary actions, social backlash, and career implications. The researchers also explore the broader implications of student sacrifices. The findings reveal that these sacrifices are driven by a profound commitment to justice and human rights, and are influenced by the increasing availability of information, peer interactions, and personal convictions. The study also discusses the broader implications of this activism, comparing it to historical precedents and assessing its potential to influence policy and public opinion. The emotional and psychological toll on student activists is significant, but their sense of purpose and community support mitigates some of these challenges. However, the researchers call for acknowledging the broader Impact of these sacrifices on the future global movement of FreePalestine.
THE SACRIFICE HOW PRO-PALESTINE PROTESTS STUDENTS ARE SACRIFICING TO CHANGE T...
Chemical Bonding
1. 1
LEARNING OUTCOMES
Explain the formation of ionic bonds;
Define and give examples of ionic solids;
Explain the formation of covalent bonds;
Define and give examples of simple
molecular solids;
Explain metallic bonding;
Relate the structure of sodium chloride to its
properties;
Chemical Bonding
Chapter 7
2. 2
LEARNING OUTCOMES
Distinguish between ionic and simple
molecular solids;
Explain the term allotropy;
Define and give examples of giant molecular
solids;
Relate the structure of diamond and graphite
to their properties
Chemical Bonding
Chapter 7
3. 3
The Electronic Structure
of Noble Gases
The noble gases like helium, neon and argon, which are in
Group 0 of the Periodic Table, are very unreactive.
They do not form bonds with other atoms.
They have fully filled outermost (valence) shells.
Except for helium, which has 2 outer electrons, all the other
noble gases have 8 outer electrons.
Chemical Bonding
Chapter 7
4. 4
The Electronic Structure
of Noble Gases
The outer shell of 8 electrons is called an octet
structure and it makes the atom very stable.
E.g. Helium, neon, argon
Atoms of other elements become stable like the
noble gases by losing or gaining electrons or by
sharing electrons.
They achieve this by forming bonds with other atoms.
Chemical Bonding
Chapter 7
5. 5
Types of Bonds
Covalent Bond Ionic Bond
Sharing of Electrons Transfer of Electrons
Between Non-metals Between Metal + Non-metal
Chemical Bonding
Chapter 7
6. 6
Ionic Bonds
When sodium reacts with chlorine, the sodium atom loses
an electron to become a positively charged sodium ion:
Chemical Bonding
Chapter 7
7. 7
Ionic Bonds
The chlorine atom gains an electron to become a
negatively charged chloride ion:
Chemical Bonding
Chapter 7
8. 8
Ionic Bonds
The positive sodium ion and the negative chloride ion then
attract each other to form sodium chloride.
Sodium chloride is called an ionic compound.
Chemical Bonding
Chapter 7
9. 9
Other ionic compounds
Another example of an ionic
compound is that formed
between magnesium and
chlorine.
Each magnesium atom
transfers 2 electrons, one to
each chlorine atom, to form
magnesium chloride.
The formula of magnesium chloride is therefore
given as MgCl2.
Chemical Bonding
Chapter 7
10. 10
Quick check 1
1. Ionic bonds are formed between a ______ and a _____.
2. A metal atom ______ an electron to form a _______ ion while
a non-metal ______ an electron to become a ________ ion.
3. The two oppositely charged ions ________ each other to form
an ______ compound.
4. An ionic bond is formed by the _________ of _______.
5. (a) Is aluminium oxide an ionic or covalent compound?
(b) State the formula of aluminium oxide.
Solution
Chemical Bonding
Chapter 7
11. 11
1. Ionic bonds are formed between a metal and a non-metal.
2. A metal atom loses an electron to form a positive ion while
a non-metal gains an electron to become a negative ion.
3. The two oppositely charged ions attract each other to form
an ionic compound.
4. Ionic bond is formed by the transfer of electrons.
5. (a) Aluminium oxide is an ionic compound.
(b) Al2O3
Return
Chemical Bonding
Chapter 7
Solution to Quick check 1
12. 12
Covalent Bonds
To achieve a more stable structure like helium, it needs one
more electron in the first shell.
So two hydrogen atoms join together and share their
electrons. A hydrogen molecule is formed.
A hydrogen atom has only one electron in its first shell.
Chemical Bonding
Chapter 7
13. 13
Covalent Bonds
This sharing of electrons is called covalent bonding.
In an oxygen atom, the outer shell has 6 electrons, so to achieve
an octet structure of 8 electrons like neon, two oxygen atoms
combine to share 4 electrons.
This is called a double bond.
Chemical Bonding
Chapter 7
15. 15
Quick Check 2
1. The joining of atoms to form a molecule is called
__________ ________ .
2. The two types of bonds are ________ bond and
________ bond.
3. Covalent bonds are formed by the _________ of
_________ .
4. Ionic bonds are formed by the __________ of_________ .
5. _________ ______ are formed between non-metals
e.g. hydrogen, oxygen and carbon.
Solution
Chemical Bonding
Chapter 7
16. 16
1. The joining of atoms to form a molecule is called
chemical bonding .
2. The two types of bonds are covalent bond and
ionic bond.
3. Covalent bonds are formed by the sharing of
electrons .
4. Ionic bonds are formed by the transfer of
electrons .
5. Covalent bonds are formed between non- metals e.g. hydrogen,
oxygen and carbon.
Return
Chemical Bonding
Chapter 7
Solution to Quick check 2
Lesson 2
17. 17
Properties of Covalent Compounds
The intermolecular forces
between the molecules are
weak so covalent
compounds have low melting
and boiling points.
For example, water, a
covalent compound, has a
melting point of 0 oC and a
boiling point of 100 oC.
Weak intermolecular
forces
Chemical Bonding
Chapter 7
18. 18
Properties of Covalent Compounds
Covalent compounds do not
conduct electricity in any
state.
Most covalent compounds
are insoluble in water.
Instead they are soluble in
organic solvents.
For e.g. iodine is insoluble in
water, but soluble in ethanol. Pure water does not
conduct electricity
water
Chemical Bonding
Chapter 7
19. 19
Properties of Ionic Compounds
The electrostatic forces
between the oppositely-
charged ions are very strong
so ionic compounds have
very high melting points and
boiling points.
For e.g. sodium chloride, an
ionic compound, has a
melting point of 801 oC and
a boiling point of 1 517oC.
Chemical Bonding
Chapter 7
20. 20
Properties of Ionic Compounds
Ionic compounds conduct
electricity when molten or
dissolved in water. This is
because the ions can move
about and conduct electricity.
Molten sodium
chloride conducts
electricity.
Most ionic compounds are soluble in
water, but insoluble in organic solvents.
For e.g. sodium chloride is soluble in
water, but insoluble in oil or petrol.
Chemical Bonding
Chapter 7
21. 21
Summary
Ionic Compounds Covalent Compounds
Have very high melting and boiling
points
Have low melting and boiling points
Conduct electricity when molten or in
aqueous solution
Cannot conduct electricity in any state
Are usually soluble in water, but
insoluble in organic solvents
Are usually insoluble in water, but
soluble in organic solvents
Differences between Ionic and Covalent Compounds
Chemical Bonding
Chapter 7
22. 22
Quick check 3
1. Covalent compounds have _______ forces of attraction
between the molecules, so they have ____ melting points and
______ boiling points.
2. Ionic compounds have very ______ forces of attraction
between the oppositely charged ions, so they have very
______ melting points and ______ boiling points.
3. All covalent compounds cannot _____ _______ .
4. All ionic compounds can conduct ________ when they are
_______ or ________ in water.
5. Sugar is a covalent compound but it is soluble in water. State
one test you would use to show that sugar is a covalent
compound.
Contd.
Chemical Bonding
Chapter 7
23. 23
Quick check 3 (cont.)
6. The table below shows 3 substances.
(a) Which substance is an ionic compound?
(b) Which substance is a metal?
(c) Which substance could be a covalent compound? Solution
Chemical Bonding
Chapter 7
Substance Electrical Conductivity
when solid when molten
A does not conduct does not conduct
B does not conduct conducts
C conducts conducts
25. 25
1. Covalent compounds have weak forces of attraction between the
molecules, so they have low melting points and low boiling points.
2. Ionic compounds have very strong forces of attraction between
the oppositely charged ions, so they have very high melting
points and high boiling points.
3. All covalent compounds cannot conduct electricity.
4. All ionic compounds can conduct electricity when they are molten
or dissolved in water.
5. Dissolve some sugar in water, then try to pass electricity through
it. The sugar solution will not able to conduct electricity.
Contd.
Chemical Bonding
Chapter 7
Solution to Quick check 3
26. 26
Substance Electrical Conductivity
when solid when molten
A does not conduct does not conduct
B does not conduct conducts
C conducts conducts
6. The table below shows 3 substances.
(a) Ionic compound: B
(b) Metal: C
(c) Covalent compound: A
Return
Chemical Bonding
Chapter 7
Solution to Quick check 3 (contd.)
27. 27
Simple molecules
Many covalent substances like water,
methane, carbon dioxide and iodine
exist as small molecules.
These compounds are said to have
simple molecular structures.
Macromolecular Structures
Chapter 7
28. 28
Macromolecules
Some covalent substances like silicon
dioxide (SiO2), diamond and graphite
are made up of very large molecules.
These substances are said to have
macromolecular structures.
Macromolecular Structures
Chapter 7
29. 29
Properties of Macromolecules
Due to the large structures of these macromolecules,
their chemical and physical properties are different
from those of the simple molecules.
The macromolecules are solids with very high melting
and boiling points.
E.g. The melting point of diamond is 3550 oC,
compared to 0 oC for water.
Due to their sizes, they are also not as reactive
compared to the simple molecules.
Macromolecular Structures
Chapter 7
30. 30
Metallic bonding
Metals are also made up of very large lattice structures.
The metallic structure consists of a lattice of positive ions
in a “sea of electrons”.
Metals are malleable because the layers of atoms can
slide over one another easily as they are being arranged
in neat layers.
Macromolecular Structures
Chapter 7
31. 31
Properties of Metallic structure
The closely packed positively charged metallic ions
form a lattice structure with the outer electrons
moving freely around the whole metallic structure.
The electrostatic attraction between the metallic
ions and the electrons holds the metallic ions tightly
in the lattice and this gives the metal a high
melting point.
The free electrons are able to move and
conduct electricity and heat.
This explains why metals are good
conductors of heat and electricity.
Macromolecular Structures
Chapter 7
32. 32
Macromolecular Structures
Chapter 7
Van der Waals Forces
-Van der Waals forces of attraction can exist
between atoms and molecules.
-They are not the same as ionic or covalent
bonds. They arise because of fluctuating
polarities of nearby particles.
-The shape and size of molecules affect the
strength of the van der Waals forces. The
larger the force, the higher the melting and
boiling point.
33. 33
Structure of diamond
In diamond, each carbon atom is linked to four other
carbon atoms by strong covalent bonds.
The carbon atoms are arranged in a tetrahedral
structure which extends throughout the whole diamond
lattice made up of millions of atoms.
The diamond structure is very rigid and the bonds are
very strong and difficult to break. This explains why
diamond is very hard and strong and has a very high
melting point (3550 ºC) and very high boiling point
(4827 ºC).
Macromolecular Structures
Chapter 7
Structure of
diamond
34. 34
Structure of graphite
In graphite, each carbon atom is linked to three other
carbon atoms in the same plane by strong covalent bonds.
The carbon atoms form six-member hexagonal rings that link up
to form flat layers.
The hexagonal rings are arranged in parallel layers with weak
forces of attraction between the atoms in each layer.
Macromolecular Structures
Chapter 7
35. 35
Properties of graphite
The covalent bonds between the atoms in each
layer are strong, and a lot of heat energy is
required to break these bonds when graphite
melts. This explains why graphite has a very
high melting point (3652 oC ).
Not all the electrons in graphite are
used in bonding. There are some free
electrons which enable graphite to
conduct electricity.
strong covalent
bonds
weak forces
The forces of attraction between the atoms in each
layer is weak. The layers can easily slide away from
each other when a force is applied. For this reason,
graphite is smooth and slippery.
Macromolecular Structures
Chapter 7
36. 36
Summary of properties
Macromolecular Structures
Chapter 7
Property Diamond Graphite
Hardness and
Texture
Very hard and strong Soft, smooth and
slippery
Melting point and
Boiling point
Very high Very high
Electrical
Conductivity
Does not conduct
electricity
Conducts electricity
37. 37
Uses of diamond
Due to their differences in properties, diamond and
graphite are used in different ways.
Diamond being hard and strong, is used for making
cutting and drilling tools.
Another use for diamond is for making jewellery.
Macromolecular Structures
Chapter 7
38. 38
Uses of graphite
Graphite being smooth and slippery, is used in making
lubricants for use in machinery, motorcar engines and
even bicycle chains.
Due to its very high melting point, graphite is used as
a heat insulator. It is used to coat the nose of a
space shuttle.
Graphite being chemically unreactive and a conductor
of electricity, is used in making electrodes for use in
electrolysis and in dry cells.
Macromolecular Structures
Chapter 7
39. 39
Quick check 4
1.The table below shows the properties of 4 substances.
Element Conducts electricity in Melting point
(OC)
Solid state Liquid state
W good good 1085
X poor good 801
Y poor poor 3550
Z poor poor 114
Deduce the type of bonds that each substance has.
Solution
Macromolecular Structures
Chapter 6
40. 40
Quick check 4 (cont’d)
2.The pictures below show 4 types of molecular structures.
Identify the substance or the type of bonds shown
by each structure.
A B
C D
Solution
Macromolecular Structures
Chapter 6