1. QOD p. 150 Vertical column *Share chemical properties group period
Horizontal Row
*Properties increase
or decrease across
the period
*Share chemical
properties

2. electrons on the outer energy level
uld
Exploring the Periodic Table:
The role of electrons →
Trends
are a result of electron
placement
Valence electrons → Na 11
electrons on the outer energy
level
(most energy!)

3. Fe A=P=E M-A=N 16 26 56 x x x x x x x x x x x x x x x x x x x x x x x
mass number
A=P=E
M-A=N Fe 56 26 x x
atomic number x x x x x x x x x x x x x x x x
Valence
26 protons
26 electrons
30 neutrons x x x
electrons x x x 16 x x

4. electrons, these elements have similar properties
Because elements in
a group have the same
amount of valence
electrons, these elements
have similar properties
Valence electrons for both =1 because they are in the same group.

5. * Elements want to have Ion = charged atom; gains or loses electrons
a full outer energy level
5B loses 3 valence electrons and becomes 5B +3
Boron
Atomic Number =5