1. 5.1

2. Ions
• When atoms are in their pure form,
they are neutral.
• Neutral atoms can become charged by:
– losing electrons
– gaining electrons
• When they do this they become IONS.

3. • Atoms become ions by obeying
the octet rule.
– All atoms want a full outer shell.
– A full outer shell = 8 electrons
Octet Rule

4. The elements are
arranged in groups

5. All elements want 8 e- in the
valence shell to be stable.
Group
#
# of
valence
electrons
electrons
lost or
gained
Ion
Charge

6. Ion Formation

7. Ionic Charge

8. Ion Formation

9. Ionic charge

10. Naming Ions
• Positive ions are
Cations
• Use the name of
the element.
• Negative ions are
Anions
• Use the root of
the element, drop
ending and add –
”ide”.K+1
Ca+2
Al+3
Potassium ion
Calcium ion
Aluminum ion
S-2
O-2
Br-1
N-3
Sulfide ion
Oxide ion
Bromide ion
Nitride ion

11. Homework
• READ: pages 158-165
–Be sure you understand the
connection between orbitals
and valence electrons!
• Do: p.165 1-13