The periodic table organizes elements by atomic number and recurring chemical properties. Elements are grouped into rows called periods and columns called groups based on their atomic structure and how they gain, lose or share electrons to form bonds. The location of an element on the periodic table can provide information about its physical and chemical properties.

1. The Periodic Table of the Elements Basic Chemistry Heartlife Physical Science

2. The Periodic Table of the Elements - Review What does the atomic number tell you? # of protons (& electrons) What does the atomic mass tell you? weight of protons & neutrons combined allows you to calculate the # of neutrons What are atomic symbols used for? abbreviations allow easier written chemical formulas H 2 O 2 , CO 2 , C 6 H 12 O 6 Which subatomic particles are found in the nucleus of an atom? protons & neutrons

3. Columns (called groups ) have similar chemical & physical properties share similar arrangement of electrons same # of valence electrons (electrons in outermost shell) Rows (called periods ) highlight the repeating nature of elements displayed in order of increasing atomic number (no other similarities) atomic radius decreases as you move left to right ionization energy increases left to right Periodic Table of the Elements - What patterns do you see?

4. Reactivity - What makes atoms interact? Atoms are happiest (most stable): with full energy levels (filled electron shells) with paired electrons Atoms will interact with other atoms to make electron pairs and filled shells happen Phosphorus

5. Drawing Chemical Reactions - Two ways to draw an atom Bohr Models show ALL electrons orbiting an atom But only valence electrons (those in the outermost shell) are involved in chemical reactions Lewis Dot Structures display ONLY the valence electrons Lewis Structure Bohr Model

6. Periodic Table of Elements - Lewis Dot Structures

7. Reactivity - Covalent Bonds Sometimes valence electrons are shared They spend part of their time orbiting each atom These shared electrons help hold the molecule together Electrons are shared by the compound's individual atoms: COVALENT BOND O Water H H

8. Bonding - Ionic Bonds Sometimes electrons are donated (and received) in this case, ions are formed (charged particles) the opposite charges of the atoms bind them together Electrons donated/received by individual atoms: IONIC BOND Table Salt

9. Three General Classes of Elements Metals ~ 80% of all elements shiny, solid (except Hg) malleable (soft, can reshape) conduct heat & electricity ductile (drawn into thin wires ) Metalloids - only 7 have properties of both metals and nonmetals all are solids Nonmetals - 2 nd largest group dull (not shiny) brittle (shatter, not bendable) good insulators more than half are gases

10. Group 1: Alkali Metals Physical Properties soft (can be cut with knife) shiny and silver low densities Bohr Diagram Lewis Structure Chemical Properties have 1 valence electron VERY REACTIVE! usually lose 1 electron in reactions never found as pure elements in nature must be stored under oil in sealed containers to prevent violent reactions Sodium in Water

11. Group 2: Alkaline Earth Metals Physical Properties hard gray-white good electrical conductors Bohr Diagram Lewis Structure Chemical Properties have 2 valence electrons less reactive than alkali metals, but more than the other metals react by losing 2 electrons never found as pure elements in nature Berryllium Magnesium Calcium Strontium Barium Radium Sr Calcium & Barium in Water

12. Group 3-12: Transition Metals Physical Properties form colored compounds most are hard & shiny good electrical conductors Bohr Diagram Lewis Structure Chemical Properties have 1 or 2 valence electrons less reactive, but unpredictable reactions can speed up reactions lose different #'s of electrons Au * Lanthanides **Actinides Copper & Zinc Reactions

13. Group 13: Boron Family Physical Properties Boron (metalloid) is hard, black solid and very brittle good conductor at high temps poor conductor at low temps Al, Ga, In, & Ti are metals good conductors, soft/malleable Bohr Diagram Chemical Properties have 3 valence electrons reactivity varies within this group Metal Salts Flame Test Boron Aluminum Gallium Indium Thallium Lewis Structure Al

14. Physical Properties Carbon (nonmetal) is found in nearly every living thing elemental forms in nature: graphite & diamonds Si & Ge are metalloids Sn & Pb are metals Group 14: Carbon Family Bohr Diagram Chemical Properties have 4 valence electrons gain, lose, or share 4 electrons when reacting with other elements Carbon Silicon Germanium Tin Lead Lewis Structure Bronze from Tin & Copper Ge

15. Physical Properties N & P are nonmetals Nitrogen is a gas at room temp All others are solids As & Sb are metalloids Bismuth is a metal Group 15: Nitrogen Family Bohr Diagram Chemical Properties have 5 valence electrons elements vary in reactivity Nitrogen Phosphorus Arsenic Antimony Bismuth Lewis Structure Phosphorus video Phosphorus Bismuth As

16. Physical Properties Oxygen is a nonmetal gas most abundant element in Earth's crust (1/5 Earth's atmosphere) Sulfur is a yellow, nonmetal solid smells like rotten eggs Group 16: Oxygen Family Bohr Diagram Selenium is a nonmetal solid conducts electricity with sunlight Te & Po are metalloids Chemical Properties have 6 valence electrons elements vary in reactivity Oxygen Sulfur Selenium Tellurium Polonium Lewis Structure Sulfuric Acid on Sugar Cubes Tellurium S

17. Physical Properties Fluorine & Chlorine are greenish-yellow gases, toxic in their pure form Bromine is a smelly, reddish-brown liquid that causes burns Iodine is a dark-gray solid Astatine is a radioactive solid Group 17: Halogens Chemical Properties have 7 valence electrons generally gain or share 1 electron all very reactive Fluorine Chlorine Bromine Iodine Astatine Lewis Structure Halogen Reactions I P:53 N:74 Bohr Diagram

18. Physical Properties All are gases easily found in the atmosphere Each noble gas creates a different color in "neon" lights Group 18: Noble Gases Bohr Diagram Chemical Properties have 8 valence electrons (except He) have full valence shells, so NOT very reactive Lewis Structure Lead Balloon Demo Ar Helium Neon Argon Krypton Xenon Radon

19. Physical Properties most abundant element in the universe doesn't fit in any group invisible gas (nonmetal), very flammable pure hydrogen is lighter than air Hydrogen Bohr Diagram Chemical Properties has only 1 valence electron forms many different compounds has NO neutrons Lewis Structure Hydrogen Bomb H