1. Subatomic particles in ions:
When atoms gain electrons they
become to negative ions (anions):
Neutral atom Cl 0 (17 p e- )
Ion Cl 1- (17 p ____ )
18 e -

2. Subatomic particles in ions:
When atoms lose electrons they
become to positive ions (cations):
Neutral atom Na 0 (11 p e - )
Ion Na 1+ ( 11 p+ + ____ )
10 e -

3. Li Li 6 3 6 3 A neutral atom of lithium has 3 protons and 3 electrons
When lithium reacts, it typically looses one electron.
Lithium ION: 3 protons (3 +) and 2 electrons (2-)
Now has a NET charge of (1+)
1 + Li 3 6

4. If no charge here: NEUTRAL ATOM (same number of protons as electrons)Li 3 6
If no charge here: NEUTRAL ATOM (same number of protons as electrons)
1 + Li 3 6
If charge here: ION
Positive charge = more protons than electrons.
Negative charge = more electrons than protons.

5. Na S Al 11 23 + 11 protons; 10 electrons; 12 neutrons. 16 32 2-13 27 3+
13 protons; 10 electrons; 14 neutrons.

6. N Ca Cl 14 41 35 7 20 17 3- 2+ Prot. Neut. Elect. Atom or Ion 7 7 10
ion Ca 20 41 2+
ion Cl 17 35
atom