| A | B |
|---|
| Period | the horizontal row on the periodic table, as you go from left to right on the periodic table the elements increase by one proton and one electron |
| Electron configuration | – the order in which the electron orbitals fill |
| Group | the vertical column in the periodic table |
| Ionization energy | the energy needed to remove an electron from an atom |
| Malleable | the ability of metals and alloys to be rolled or hammered into thin sheets |
| ductile | the ability of metals to be drawn into wires |
| luster | property of metals and alloys that describes having a shiny appearance or reflecting light |
| allotropes | different forms of the same element having different molecular structures |
| metals | element that typically is a hard , shiny solid, is malleable , and is a good conductor of heat and electricity |
| nonmetal | element that usually is a gas or brittle solid at room temperature , is not malleable or ductile, is a poor conductor of heat and electricity, and is usually not shiny |
| diatomic molecule | a molecule that consists of two atoms of the same element |
| metalloid | element that shares some properties with metals and some with nonmetals |
| compound | substance formed from two or more elements in which the exact combination and proportion of elements is always the same |
| element | substance with atoms that are all alike |
| molecule | a neutral particle that forms as a result of electron sharing |
| ionic bond | attraction formed between oppositely charged ions in an ionic compound |
| polar molecule | molecule with a slightly positive end and a slightly negative end as a result of electrons being shared unequally |
| ion | charge particle that has either more of fewer electrons than protons |
| electronegativity | is a description of the atom’s energetic ‘need’ for another electron |
| stable | unlikely to chemically react |
| cations | positive ions |
