| 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/volume |
| physical characteristics | no change to the original substance |
| chemical characteristics | changes into a different substance |
| atom | smallest particle identifiable as that substance |
| molecule | more than one atom CONNECTED together |
| heterogeneous mixture | rocks, sand and water |
| homogeneous mixture | sugar dissolved in water |
| electron | negatively charged, no mass |
| nucleus | center of atom-protons and neutrons |
| charge on an electron | -1 |
| charge on a proton | +1 |
| charge on a neutron | no charge |
| identifies an element | atomic number/number of protons |
| how many protons and neutrons? | =mass number |
| isotope | same # of protons/different number of neutrons |
| compound | substance made of2 or more different atoms |
| gamma ray | has no mass, deadliest form of radiation |
| alpha particle | weakest form of nuclear radiation, like an He nucleus |
| beta particle | strong or weak, like an electron |
| alloy | solution of metals |
| pure substance | made of one type of atom, compound or molecule |
| U238 | alpha decays to Thorium-234 |
| U235 | gamma decay/ also fissionable |
| nuclear reactors | use nuclear power to heat water |
| Fukashima | recent nuclear disaster |
| Chernobyl | worst nuclear disaster |
| 3 Mile Island | American (PA) nuclear accident |
| Half-life | time required for half of a substance to decay |
