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!

How do you read the PERIODIC TABLE?

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

Group 1: Alkali Metals

Group 2: Alkaline Earth Metals

Group 17: Halogens

Group 18: Noble Gases (Inert)

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

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)

Metalloids HHave properties of metals & non- metals SSolids that can be shiny or dull DDuctile & malleable CConduct heat & electricity better than non-metals BUT not as well as metals

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

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

Equations: Reactant & Products NaCl + NaOH  NaCl + H 2 O Reactants Products

Count Number of Atoms in a Given Molecule  How many atoms are in each of the following molecules?  O 3  N 2  H 2 O  CO 2  NH 3

Count Number of Atoms in a Given Molecule  How many atoms of each of element are in each of the following molecules?  O 3 = 3 Oxygen = 3 total  N 2 = 2 Nitrogen = 2 total  H 2 O = 2 Hydrogen, 1 Oxygen = 3 total  CO 2 = 1 Carbon, 2 Oxygen = 3 total  NH 3 = 1 Nitrogen, 3 Hydrogen = 4 total

Identifying a Balanced Equation  2CaCl  Ca + 2Cl  CaCl 2 + H 2 O  Ca + ClH + O 2  CaCl 2 + Cl  Ca + Cl 3  CaCl 2  Ca + Cl 2  CH 4 + 2O 2  CO 2 + 2H 2 O  2HCl + NaOH  2H 2 O + NaCl  HCl + NaOH  H 2 O + NaCl  HCl + 2NaOH  H 2 O + 2NaCl  2HCl + 2NaOH  H 2 O + 2NaCl

Identifying a Balanced Equation  2CaCl  Ca + 2Cl  CaCl 2 + H 2 O  Ca + ClH + O 2  CaCl 2 + Cl  Ca + Cl 3  CaCl 2  Ca + Cl 2  CH 4 + 2O 2  CO 2 + 2H 2 O  2HCl + NaOH  2H 2 O + NaCl  HCl + NaOH  H 2 O + NaCl  HCl + 2NaOH  H 2 O + 2NaCl  2HCl + 2NaOH  H 2 O + 2NaCl

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

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:

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

Potential & Kinetic Energy  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 Potential Kinetic

Units for Electricity in our House KKilowatt-hour = unit for electricity EElectricity is the typical form of energy that we use in our homes

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

Energy Transformations: Fossil Fuels  Fossil fuels such as gas, oil, and coal have what kind of energy? C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? CCars

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

Energy Transformations: Photosynthesis  Describe the energy transformation in photosynthesis:  Light energy  chemical energy

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. LLight energy into electricity