PERIODIC TABLE, CHEMICAL & PHYSICAL CHANGES, CHEMICAL REACTIONS, & ENERGY

1. PERIODIC TABLE, CHEMICAL & PHYSICAL CHANGES, CHEMICAL REACTIONS, & ENERGY We’re all looking forward to this SOL Test…or at least looking forward to it being over!

2. How do you read the PERIODIC TABLE?

3. Atomic Mass & Atomic Number • Atomic Number = The number of protons found in the nucleus of an atom • Whole number found on the periodic table • Atomic Mass = The number of protons and neutrons in the nucleus of an atom. • Also known as the atomic weight or mass number

4. Group 1: Alkali Metals

5. Group 2: Alkaline Earth Metals

6. Group 17: Halogens

7. Group 18: Noble Gases (Inert)

8. Metals • Good conductors of heat and electricity • Shiny • Ductile: can be stretched into thin wires • Malleable: can be pounded into thin sheets • Reacts with water which results in corrosion (rust!) • Examples: gold, zinc, silver, aluminum, copper & bronze

9. Non-Metals • Poor conductors of heat and electricity. • NOT ductile or malleable • Solid non-metals are brittle and break easily • Dull • Many non-metals are gases • Examples: wood, cloth, plastic, air (insulators)

10. Metalloids • Have properties of metals & non-metals • Solids that can be shiny or dull • Ductile & malleable • Conduct heat & electricity better than non-metals BUT not as well as metals

11. Physical Change • A change that alters the form or appearance of a material but does not convert the material into new substances • Examples: • Chopping wood • Ripping paper • Water – changing from ice, liquid water, water vapor • Crumbled aluminum foil • The mixture of yellow sulfur powder and iron fillings • Adding salt to water • Sharpening a pencil • Adding food coloring to water

12. Chemical Change • Chemical Reaction • A change in matter that produces new substances • The new substance is made up of the same elements as the original substance, but the atoms are rearranged in new combinations • Examples: • Burning a candle wick • Rusting metal • Burning wood • The compound between iron and sulfur – called iron sulfide or pyrite or fool’s gold • Chemical reaction between vinegar & baking soda

13. Equations: Reactant & Products NaCl + NaOH  NaCl + H2O Products Reactants

14. Count Number of Atoms in a Given Molecule • How many atoms are in each of the following molecules? • O3 • N2 • H2O • CO2 • NH3

15. Count Number of Atoms in a Given Molecule • How many atoms of each of element are in each of the following molecules? • O3 = 3 Oxygen = 3 total • N2 = 2 Nitrogen = 2 total • H2O = 2 Hydrogen, 1 Oxygen = 3 total • CO2 = 1 Carbon, 2 Oxygen = 3 total • NH3 = 1 Nitrogen, 3 Hydrogen = 4 total

16. Identifying a Balanced Equation • 2CaCl  Ca + 2Cl • CaCl2 + H2O  Ca + ClH + O2 • CaCl2 + Cl  Ca + Cl3 • CaCl2  Ca + Cl2 • CH4 + 2O2  CO2 + 2H2O • 2HCl + NaOH  2H2O + NaCl • HCl + NaOH  H2O + NaCl • HCl + 2NaOH  H2O + 2NaCl • 2HCl + 2NaOH  H2O + 2NaCl

17. Identifying a Balanced Equation • 2CaCl  Ca + 2Cl • CaCl2 + H2O  Ca + ClH + O2 • CaCl2 + Cl  Ca + Cl3 • CaCl2  Ca + Cl2 • CH4 + 2O2  CO2 + 2H2O • 2HCl + NaOH  2H2O + NaCl • HCl + NaOH  H2O + NaCl • HCl + 2NaOH  H2O + 2NaCl • 2HCl + 2NaOH  H2O + 2NaCl

18. Understanding Chemical Reactions • Electrons in the highest occupied energy level of the atoms are responsible for chemical reactions • When two elements react, they chemically combine to form a new compound

19. What factors increase Solubility? • For Example: Solute = salt, Solvent = water • Grinding salt to make the salt crystals smaller • Stirring the water after adding the salt • Increasing the temperature of the water • So, we’re looking for things that will help things dissolve faster:

20. Examples of Potential & Kinetic Energy • Classify the following as potential or kinetic energy: • A glass jar sitting on a shelf • A flag waving the wind • A ball rolling along a sidewalk • Water stored behind a dam • A train moving down a track • Electric charges moving in a straight path • A plate sitting on the edge of the table • A baseball moving from the pitcher to the catcher • A rock sitting on the top of a large hill • A pendulum at the top of its swing

21. Potential & Kinetic Energy Potential Kinetic • A glass jar sitting on a shelf • Water stored behind a dam • A pendulum at the top of its swing • A rock sitting on the top of a large hill • A plate sitting on the edge of the table • A flag waving the wind • A ball rolling along a sidewalk • Electric charges moving in a straight path • A train moving down a track • A baseball moving from the pitcher to the catcher

22. Units for Electricity in our House • Kilowatt-hour = unit for electricity • Electricity is the typical form of energy that we use in our homes

23. Energy Transformations: Batteries • Describe the energy transformation involved with a battery operated flashlight • Describe the energy transformation involved with a car battery causing headlights to shine. • The answer for both of the above: • chemical  electrical  light

24. Energy Transformations: Fossil Fuels • Fossil fuels such as gas, oil, and coal have what kind of energy? • Chemical Energy • What is the energy transformation that occurs first in a coal-burning power plant? • Chemical energy to thermal energy • Fossil fuels are important for what that we use nearly everyday? • Cars

25. Examples of Energy Transformations • Describe the energy transformation involved in a burning candle. • Chemical energy  light & heat • Describe the energy transformation involved in a toaster. • Electricity  Heat

26. Energy Transformations: Photosynthesis • Describe the energy transformation in photosynthesis: • Light energy  chemical energy

27. Renewable Energy Transformations • What form of energy does a windmill use to turn? • Mechanical Energy • What is a limitation of windmills? • The strength of the wind varies. • Describe the energy transformation involved in solar panels. • Light energy into electricity