| A | B |
|---|
| electrons | negatively charged particles found outside the nucleus of an atom |
| neutrons | particle found in the nucleus of an atom, it has no charge |
| energy levels | orbits in which electrons circle the nucleus |
| protons | positively charge particle found in the nucleus of an atom |
| orbitals | where the electrons are most likely to be found around the nucleus |
| atomic mass units | unit used for measuring the mass of an subatomic partic |
| atomic mass | the sum of the relative masses of all the protons and nuetrons in an atom |
| mass number | the atomic mass rounded to the nearest whole number |
| atomic number | of an element, it is the number of protons found in the nucleus |
| isotopes | atoms with the same number of protons, but different number of nuetrons |
| ion | when an atom loses or gains an electron |
| when an atom has more protons than electrons you have an ion with a | positive charge |
| periods | arrangement of elements in the periodic table of elements in rows |
| carbon | C |
| iron | Fe |
| Aluminum | Al |
| magnesium | Mg |
| lead | Pb |
| oxygen | O |
| sulfur | S |
| calcium | Ca |
| chlorine | Cl |
| gold | Au |
| helium | He |
| nitorgen | N |
| phosphorus | P |
| potassium | K |
| silicon | Si |
| sodium | Na |
