| A | B |
|---|
| Oxygen | Most abundent element in earth's crust. |
| Dmitri Mendeleev | Russian who invented the periodic table of elements. |
| Chemical Property | not reversible change, turns into new substance |
| Periodic Table | chart of all known elements. |
| Period | horizontal row on periodic table. |
| Group | Vertical columns of periodic table. |
| Metal | good conductor or electricity |
| Non Metal | Good insulators, poor conductors |
| atomic mass | sum of protons and neutrons |
| alkali metals | Highly reactive first group. |
| Group 2 Metals | Somewhat reactive 2nd group. |
| Halogens | Group 17 on periodic table. |
| Noble Gases | Group 18. Does not like to react. |
| Periodicity | Repeating patterns of chemical and physical properties on periodic table. |
| Electrical Conductor | metals have this property |
| Thermal Insulator | non metals have this property |
| Steel | alloy of iron |
| Carbon | Important for life. |
| Nitrogen | 72% of earth's atmosphere |
| Physical Property | Properties like melting, boiling; substance DOES NOT change |
| Valence Electron | electron(s) in the outermost energy level or ring of an atom. |
