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
Have properties of metals & non-metals
Solids that can be shiny or dullDuctile & malleableConduct 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 woodRipping paperWater – changing from ice, liquid water, water vapor
Crumbled aluminum foilThe mixture of yellow sulfur powder and iron fillingsAdding salt to waterSharpening 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 goldChemical reaction between vinegar & baking soda
Equations: Reactant & Products
NaCl + NaOH NaCl + H2OReactants Products
Count Number of Atoms in a Given Molecule
How many atoms are in each of the following molecules?
O3
N2
H2O CO2
NH3
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
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
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
Understanding Chemical ReactionsElectrons 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 HouseKilowatt-hour = unit for electricity
Electricity is the typical form of energy that we use in our homes
Energy Transformations: BatteriesDescribe 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? 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
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.
Light energy into electricity