1. Trends in the Periodic Table

2. Trends in Mass
As you move from left to right across a period, mass increases
As you move from top to bottom down a group, mass increases
Masses get larger in both these cases as the atoms have more protons, neutrons and electrons

3. Trends in Atomic Radius
As you move from left to right across a period atomic radius DECREASES!!
This is because the electrons are “pulled in” closer to the nucleus as the number of protons increases….the atom “shrinks” in a bit.
See graph on p. 23

5. Trends in Atomic Radius
As you move from top to bottom down a group, atomic radius INCREASES as the atoms have more electron shells.

8. Trends in Reactivity for Metals
As you move from left to right across a period, reactivity decreases for metals
As you move from top to bottom down a group, reactivity increases for metals
The most reactive metal is francium (Fr)

9. Trends in Reactivity for Non-metals
As you move from left to right across a period, reactivity for non-metals increases
As you move from top to bottom down a group, reactivity for non-metals decreases.
Remember the noble gases are NON-REACTIVE, so the most reactive non-metal is fluorine (F)

10. Trends in Ionization Energy
Ionization energy is the energy required to remove the outermost electron from an atom
Ionization energy increases across a period and decreases down a group

11. Trends in Ionization Energy