1. Unit 3
Periodic Trends

2. Atoms get smaller and heavier (more dense)

3. The number of valence electrons increases by one on each column.1
FULL 2 3 4 5 6 7

4. Solids on the Left / Gases on the Right
There are only 2 liquids (bromine and mercury)

5. Metals on the Left / Nonmetals on the Right
Metalloids form a “staircase” between the two sides

6. Atoms get both bigger in size, and heavier

7. Noble gases are always stable
(unreactive)
Nonmetals get more reactive at the top
Metals get more reactive at the bottom.