science gcse core, additional and triple powerpoints

1. Chemical patterns Route map Over the next 12 lessons you will study : Friday 21 October 2011 C4.1 The periodic table C4.2 The alkaline metals C4.3 Chemical equations C4.4 The halogens End of module test C4.5 The discovery of helium C4.6 Atomic structure C4.7 Electrons in atoms C4.8 Electronic structures and periodic table C4.9 Salts C4.10 Ionic theory C4.11 Ionic theory and atomic structure C4.12 Chemical species

3. C4.1 The periodic table Extension questions: 1: What is the definition of a) an element and b) a compound ? 2: Give three properties shared by all metals and three properties shared by all non metals ? 3: Using the periodic table identify a) a group one metal b) a halogen gas c) a semi metallic element d) a gaseous element required for respiration e) a group II metals more reactive than magnesium ? 4: Compared to the element hydrogen, how many times heavier is a) a sulphur atom b) a carbon atom and c) an oxygen atom ? Know this: a: Know that the periodic table places elements in groups with similar chemical properties. b: Know that each element has a mass relative to hydrogen. Friday 21 October 2011 Introduction: Elements in the periodic table are arranged by their atomic number which is determined by the number of protons each element contains. Using this rule gives rise to groups or columns of elements with similar chemical and physical properties. There are eight distinct groups of elements, for example group one elements are the reactive alkaline metals. There are also five periods or rows. Between groups II and III are the elements known as the transitional metals.

4. C4.1 a Look at the photograph and information and answer all the questions: The periodic table is a tabular display of the chemical elements. Its invention is credited to Russian chemist Dmitri Mendeleev in 1869, who intended the table to illustrate recurring trends in the properties of the elements. The layout of the table has changed and been extended over time, as new elements have been discovered. Every element has its own unique symbol. Name a) reactive metal b) halogen solid, c) element found in diamond and graphite d) yellow non metal element e) liquid metal at room temperature ? In the middle of the table are the transitional metals. Give two uses for a) copper b) iron c) gold and e) silver ? In the picture below left, explain why are there gaps in the first periodic table developed by Mendeleev in 1869 ? The periodic table Mendeleev’s periodic table Key concepts

5. C4.1 b Look at the photograph and information and answer all the questions: There are over 100 elements found in the periodic table. Each element has its own unique physical and chemical properties. The largest group of elements with similar properties are the metals, for example iron, sodium, copper, zinc, and gold. The non metals include elements like carbon, neon, chlorine, fluorine, sulphur and oxygen. The halogens including chlorine and fluorine have antiseptic properties. Give three products where you find these elements ? Give three elements that exist as gases at room temperature ? Name a) one reactive metal b) one un-reactive metal c) an element form group VI d) a semi metallic element ? Key concepts

6. C4.1 Plenary Lesson summary: elements table metal period Friday 21 October 2011 In periods 2 and 3 which contain exactly 16 elements from lithium through to Argon, the physical and chemical properties of each element in each of the eight groups repeat themselves. How they behave chemically with other elements and compounds is determined by their electron configuration How Science Works: Research into the alkaline metals, potassium, sodium and lithium, their uses and their physical and chemical properties. Preparing for the next lesson: The periodic _______ arranges the _______ in columns called groups and in rows called a __________. Each row or period starts with a reactive ________ and ends with a un reactive non metal. Decide whether the following statements are true or false : False True 3: Metallic elements are more numerous than non metal elements ? False True 2: An example of an element in found in group 8 is neon ? False True 1: In group II there are both non metal and metal elements ?

8. C4.2 The alkaline metals Extension questions: 1: Give the symbols of the following alkaline metals Lithium, sodium and potassium ? 2: Potassium, sodium and lithium can be cut with a knife. Is this a typical property of all metals ? 3: When freshly cut, predict which metal lithium, sodium or potassium will tarnish in air the fastest ? 4: If you reacted sodium metal with chlorine gas, what product would you form and how does the product differ form the substrates ? Know this: a: Know which metals are found in the periodic table. b: Know the reactions of the group I metals with water, oxygen and acids. Friday 21 October 2011 Introduction: The group one elements, the alkaline metals are all reactive metals able to form compounds with other non-metal elements like chlorine and oxygen and simple compounds like water and acids. They have similar physical and chemical properties. They all have a typical shiny metallic appearance when freshly cut, but all tarnish within minutes of contact with air. They all have to be stored under oil so they don’t react with either oxygen or water vapour. Like all metals, they are good conductors of heat and electricity, but they have low melting and boiling points.

9. C4.2 a Look at the photograph and information and answer all the questions: Group I of the periodic table contains a family of very reactive metals known as the alkaline metals. This group contains lithium, sodium, potassium and rubidium. They are not found in their pure state like gold, but are found tied up in compounds. These metal have relatively low melting points and densities, when compared to transitional metals like copper and iron. Explain what products are formed if a) sodium is combusted in oxygen and b) lithium is reacted with chlorine gas Why are the alkaline metals not useful for building objects like cars, bridges and planes ? When potassium, sodium or lithium react with water they all form their hydroxide which is strongly alkaline. If you tested the pH what colour would the pH paper be ? Group 1 alkaline metals Key concepts Li 3 Na 11 K 19 Rb 37 Li 3 Li 3 Na 11 Na 11 K 19 K 19 Rb 37 Rb 37 7 23 39 86

10. Look at the photograph and information and answer all the questions: Understanding how metals like those found in group I react by losing their outermost electron during a chemical reaction can help us understand about reactivity. Rubidium is the most reactive and lithium the least reactive group I metal. This is because as atoms become bigger, the outermost electrons are held less tightly by the positive nucleus. This makes it easier to remove during a chemical reaction. What forces of attraction keep electrons in their electron shells Describe the relative size of the forces of attraction between the nucleus and the outermost electrons of the lithium and rubidium atoms ? Explain why sodium is less reactive than potassium during a reaction with water ? 2,1 2,8,1 Li Na K 2,8,8,1 Rb 2,8,8,18,1 Sodium atom Electronic configuration of group I metals Potassium atom Rubidium atom Lithium atom C4.2 b Key concepts

11. C4.2 Plenary Lesson summary: water periodic sodium alkaline Friday 21 October 2011 When taken out of oil, potassium, sodium and lithium are soft, shiny metals that can be cut with a knife and readily tarnish in air. In order to tell them apart simply place a small sample in a bunsen burner with a blue flame. Potassium will give a lilac colour, sodium an orange colour an lithium a red colour How Science Works: Research into how elements can be represent by their own unique symbol and how balanced chemical equation represent what happens during a chemical reaction. Preparing for the next lesson: Potassium, _________ lithium are all metals that belong to the ________ metals found in group I of the ________ table. They react readily with oxygen, _______ and acids. They have to be store in oil when not in use. Decide whether the following statements are true or false : False True 3: The alkaline metals are extracted using electrolysis ? False True 2: Potassium, sodium and lithium have low densities and all float on water ? False True 1: Sodium is more reactive than potassium and less reactive than lithium ?

13. Decide whether the following statements are true or false: Introduction: During a chemical reaction substrates atoms or molecules are rearranged to form new products. During any chemical reaction mass is always conserved, that means, the mass of products is always the same as the mass of substrates that you started with. A reaction can be described by a word or symbol equation: Methane + oxygen Carbon dioxide + Water CH 4 (g) + 2O 2 (g) CO 2 (g) + H 2 O (l) Extension questions: 1: Look at the equation above and tally the number and type of atoms on the left hand side (LHS) and right hand side (RHS) of the equation ? 2: If you react 2.4 g or magnesium with 1.6 g or oxygen, how much magnesium oxide would be produced ? 3: Write a word equation for the following reaction: a) CaCO 3 CaO + CO 2 b) CaCO 3 + HCl CaCl 2 + CO 2 + H 2 O ? 4: Explain why melting 10 g of ice produces 10 g of water ? 5: Give three visual signs that show a chemical change take place ? Know this: a: know that a chemical reaction is where substrates react to form new products. b: Know that a word or symbol equation (balanced) shows us what substrates we start with and what products we finish with. Friday 21 October 2011 C4.3 Chemical equations LHS RHS

14. C4.3 Look at the photograph and information and answer all the questions: All chemical reactions involve the formation of new products by substrates colliding with one another, breaking bonds, forming new chemical bonds and products. During the rearranging of particles in the substrates to form new products not particles are lost, so the total mass stays the same. In this example: 16g of methane (CH 4 ) react with 64 g of oxygen (20 2 ) producing 44 g of carbon dioxide (CO 2 ) and 36 grams of water (H 2 O). In the above example work out in grams the total mass of substrates (CH 4 and 2O 2 ) and the total mass of products (CO 2 and H 2 0) ? If you mix 10 g of calcium carbonate (CaCO 3 ) and 50 g of hydrochloric acid (HCl) what mass of products would you expect to make ? One of the products is carbon dioxide gas which escapes into the atmosphere...how would this affect the mass of products formed ? O 2 CH 4 H 2 O CO 2 Key Substrates Products CH 4 + 2O 2 CO 2 + 2H 2 O 16 g 64 g 44g 36 g Substrates Products Key concepts

15. C4.3 Plenary Lesson summary: Decide whether the following statements are true or false : False True False True False True compounds atoms law change Friday 21 October 2011 The law of conservation states that there is no change in mass during a reaction, however we often see an increase or decrease in mass. This is because we do reactions in open systems. For example, If you react a metal with an acid, the gas that bubbles through the reaction mixture escapes into the air. How Science Works: Research into the halogen a family of reactive non metals found in group 7 of the periodic table. Look into their physical and chemical properties Preparing for the next lesson: T. The _____ of conservation states that there is no mass _________ during a chemical reaction from beginning to end. When a reaction starts, the ______ or molecules in the substrates collide with other atoms forming new molecules of new _________. 3: During a reaction, the mass of the substrates and products is the same ? 2: Melting ice is a good example of a chemical change ? 1: When magnesium reacts with oxygen from the air, the overall mass decreases ?

17. Extension questions: 1: At room temperature, which halogen is a dark purple solid and which is a pale yellow gas ? 2: Give a) one product that contains a compound of chlorine and b) a compound of fluorine? 3: From physical data, chlorine’s melting and boiling point is -101 o C and -35 o C. Between what temperatures would chlorine be a solid, liquid and gas. 3: Write an equation between a) sodium and chlorine b) potassium and bromine and c) iron and chlorine ? Know this: a: Know that the group 7 elements are a family of reactive non metals that include fluorine and chlorine. b: Know the chemical and physical properties of the halogens. Friday 21 October 2011 Introduction: Group VII of the periodic table contains a family of very reactive non-metals known as the halogens. This group contains fluorine, a pale yellow gas, chlorine a pale green gas, bromine a dark brown liquid and iodine a dark purple solid. They are not found in their pure state like gold, but are found tied up in covalent or ionic compounds. They have low melting and boiling points and do not conduct electricity at all C4.4 The halogens

18. C4.4 Look at the photograph and information and answer all the questions: The group VII elements, the halogens are well known for their antiseptic properties. Although they are very toxic to humans at high doses, small quantities of the halogens or their ions (F- Cl- Br- & I-) have an antiseptic effect, destroying many microbes. Our drinking water is now chlorinated. Our toothpaste now contains fluoride. Before surgery, iodine water is applied to our skin. Which halogen is a) dangerously corrosive and b) used in water to disinfect skin prior to surgery and c) use in toothpastes ? Write a word equation for the formation of iron chloride from passing green chlorine gas over hot iron wool ? If you passed fluorine instead of chlorine over hot iron wool a) what product would e formed and b) would the reaction be less of more violent ? Group 7 halogens Key concepts

19. C4.4 Plenary Lesson summary: colour reactive fluorine melting Friday 21 October 2011 The halogens all have antiseptic properties because in compounds or even dissolved in water they all can punch holes in the membranes of most microbes including bacteria. Chlorine is used to sterilised the water we drink and swim in, fluoride is used in toothpaste and iodine in water is used to sterilise skin prior to surgery How Science Works: Research into how the element helium was discovered and how the presence of other elements can be detected by doing a simple flame test. Preparing for the next lesson: The group 7 elements are a family of ________ non metals beginning with ___________ and ending with iodine. As you descend the group their __________ points increase and their ______ darkens. They all have antiseptic properties in compounds and are sued to destroy microbes found in water, on teeth and skin Decide whether the following statements are true or false : False True 3: Fluoride is found in both tap water and toothpaste and kills bacteria ? False True 2: Chlorine can also decolourise fibres and is used in hair dyes ? False True 1: Iodine in water is used to disinfect floors and toilets ?

21. C4.5 The discovery of helium Extension questions: 1: Helium comes form the Greek work Helios meaning sun. Why is this an appropriate name for the element helium ? 2: Explain why helium was discovered on the sun’s surface rather than here on Earth ? 3: Helium is only found trapped under bed rock with natural gas. Explain why we eventually run out of helium gas ? 4: Give two uses for helium gas ? 5: Why is helium used instead of hydrogen to provide airships lift ? Know this: a: Know that each element give a characteristic colour spectrum when burnt. b: Know that we can identify elements present if we do a simple flame test. Friday 21 October 2011 Introduction: Each element when burnt in a blue flame gives a unique flame colour. More detailed analysis using a spectroscope shows us that each element found in the periodic table has its own colour spectrum. Using this method scientists can identify elements contain in samples and even in 1892 during a solar eclipse scientists analyse the colour spectrum form the corona of the sum and discover that the sun contained not just hydrogen gas but also helium.

22. C4.5 Look at the photograph and information and answer all the questions: Give one use of a) Neon, b) Helium and c) Argon ? If you filled two balloons, one with helium, the other with argon and release describe what you would see ? The noble gases were not discovered until 1892, where scientists discovered that, when all the nitrogen and oxygen from a sample of air was reacted with hot magnesium, there was around one percent of the gas that would not react. This small fraction contained neon, argon and krypton. Helium was first discovered by analysing the colour spectra of the sun during a total lunar eclipse. Helium on Earth was discovered with deposits of natural gas found under the bedrock. Group 8 Noble gases Key concepts Nitrogen Oxygen Noble gases CO 2

23. C4.5 Plenary Lesson summary: combusted neon colour difficult Friday 21 October 2011 Fireworks using many different metal elements to give out the brilliant colours that we all enjoy. They use potassium for lilac, sodium for orange, copper for green, lithium for red and magnesium for a brilliant white flame. How Science Works: Research into the atom, the atomic structure and the three sub atomic particle , neutrons, protons and electrons. Preparing for the next lesson: Elements like helium, ______ and argon that are un-reactive or found in unusual places are ________ to find. Using their __________ spectrum produced when __________ in a bunsen burner flame can help us detect the presence of these elements . Decide whether the following statements are true or false : False True 3: It is possible to analyse mixture of elements sing the flame colour test ? False True 2: Potassium when combusted give a bright green flame ? False True 1: Lithium when combusted give a bright red flame ?

25. C4.6 Extension questions: Using the periodic table find or answer ? 1: The element with one more proton than sodium ? 2: The element with an relative atomic mass of 17 2: Three elements with 7 electrons in their outermost shell ? 4: The element which contains 22 protons in its nucleus ? 5: The element that has two electrons in its first shell and five electrons in its second shell ? Know this: a: Know the anatomy of the atom. b: Know that every type of atom of any element is made form three sub atomic articles protons, electrons and neutrons. Friday 21 October 2011 Introduction: All atoms consist of three sub-atomic particles, neutrons, protons and electrons. The simplest atom is hydrogen. Its nucleus contains a single proton with a single positive charge. There is a single electron in orbit of the positive nucleus. Because the charges are equal, but opposite, the atom is neutral. It is the attraction between the electron and proton that holds the electron in it’s orbit. Helium has two protons and two neutrons in its nucleus with two electrons held in orbit Atomic structure

26. C4.6 a Look at the photograph and information and answer all the questions: Until 1924 most scientists thought that the tom was solid with a uniform density. Rutherford was the father of the atom suggesting for the first time that electrons orbited the nucleus which contained most of the mass of the atom. All atoms arrange their sun atomic particles in this way. Which element from the six shown by the diagram opposite left has no neutrons in the nucleus of tits atom ? Nitrogen has 7 protons, 7 electrons and 7 neutrons. Using the diagram opposite left predict and draw an atom of nitrogen Give the names of all the eight elements found in the period that begins with lithium metal ? 3P + 4N 3E - 2P + 2E - 2N 1P + 1E - Beryllium Boron Carbon Hydrogen Helium Lithium Key concepts H 1 1 He 2 4 Li 3 7 6P + 6N 6E - Be 4 9 B 5 11 C 6 12 5P + 6N 5E - 4P + 5N 4E -

27. C4.6 b Look at the photograph and information and answer all the questions: Rutherford repeated and checked his experiments many times before he published his findings. Why was this an important thing to do ? Why is the statement ‘firing a gun at a tissue and finding some of the bullet bouncing back a good analogy of what this experiment showed ? Rutherford performed an experiment where he fired alpha particles at thin gold foil. Detectors were positioned at every angle to find how the alpha particles were scattered by the gold atoms. It was discovered that some alpha particles were reflected back to the source – rather like firing a gun at tissue paper and finding some of the bullets bouncing back. He proposed that each atom had a tiny core or nucleus with a mass and a positive charge. This charge repelled the alpha particles. Most particles are undeflected Rutherford's experiment Rutherford's experiment Key concepts Alpha particles Gold atoms

28. C4.6 Plenary Lesson summary: neutrons electrons nucleus atoms Friday 21 October 2011 Atoms are composed of three type of particles: protons, neutrons, and electron. Protons and neutrons are responsible for most of the atomic mass e.g in a 75 Kg person, 74 Kg and 975 g are protons and neutrons while only 28 g are electrons. The mass of an electron is very small (9.108 X 10 -28 grams). How Science Works: Research into how electrons are arranged in shells around the positively charged nucleus. Preparing for the next lesson: All __________ consist of three basic sub-atomic particles. The _______ of the atom is very small contains most of the mass and is home to the protons and ___________. The ______ orbit in shells around the positively charged nucleus. Decide whether the following statements are true or false : False True 3: An atom had no charge with an equal number of electrons and protons ? False True 2: An atom contains four sub-atomic particles ? False True 1: Protons and electrons are found in the nucleus ?