| A | B |
|---|
| Henry Mosely | Modern periodic chart |
| Demitri Mendeleev | ordered by atomic mass |
| Periods or rows | horizontal |
| Families or groups | vertical |
| atomic mass | Elements ordered by Mendeelev |
| atomic weight | Elements ordered by Mosely |
| malleable | Able to be hammered out into thin sheets |
| ductile | Able to be drawn out into wires |
| luster | shininess |
| conductors | heat and electricity |
| corrosion | gradual wearing away of a metal |
| seven | periods |
| eighteen | families |
| tend to gain electrons | non-metals |
| tend to lose electrons | metals |
| metals | left of zig-zag line |
| non-metals | right of zig-zag line |
| metalloids | on either side of zig-zag line |
| active solid | First element in a period |
| inactive gas | Last element in a period |
