| A | B |
|---|
| solid | keeps shape, fixed volume |
| liquid | takes shape of container, fixed volume |
| gas | fills container, no fixed volume |
| reactants | combine to make products |
| products | made of reactants |
| matter | has mass and volume |
| density | mass divided by volume |
| physical change | no change to the original substance |
| chemical change | changes the substance into something else |
| atom | smallest particle of a substance identifiable as the substance |
| molecule | more than one atom connected together |
| heterogeneous mixture | rocks, sand and shells |
| homogeneous mixture | sugar dissolved in water |
| electron | negative charge, in electron cloud |
| nucleus | center of atom--protons and neutrons |
| charge on an electron | -1 |
| charge on a proton | +1 |
| charge on a neuton | no charge |
| identifies and element | atomic number, the number of protons |
| how many protons and neutrons? | mass number |
| isotope | same # of protons, different # of neutons |
| 1s2, 2s2, 2p4 | electron configuration of Oxygen |
| 1s2, 2s2, 2p3 | electron configuration of Nitrogen |
| 6.02 x 10 to the 23rd power | 1 mole |
| 1.2 x 10 to the 24th power | 2 moles |
| valence electron | outer shell (ring) electron |
| group on periodic table | columns |
| period on periodic table | rows |
| Halogens | group 17 |
| Noble gases | group 18 |
| alkali metals | group 1 |
| alkaline earth metals | group 2 |
| transition metals | not groups 1,2,17,18 |
| electronegativity | how hard an atom wants to grab electrons |
| F | highest electronegativity on table |
| Ionization energy | how much energy is needed to give up an atom |
| Group 1 | lowest ionization energy |
| cations | positive ions, have given up an electron |
| anions | a negative ion, gains an electron |
| polyatomic ion | made of more than one element |
| Na2 CO3 | Sodium Carbonate |
| criss cross rule | to balance the charges |
| Charge on aluminum ion | +3 |
| all negative simple ions end in___ | -ide |
| NaCl | sodium chloride |
| NH4 Cl | ammonium chloride |
| NH4 Br | ammonium bromide |
| Potassium sulfate | K2 SO4 |
| Potassium nitrate | N (NO3)3 |
| Number of Cl's in aluminum chloride | 3 (Al Cl3) |
| Number of NH4 molecules in ammonium sulfate | 2 (NH4)2 SO4 |
