Download Period Table, valence Electrons and Ion Notes

Periodic Table Notes
IONS
Ion- a charged atom (# of electrons change)
Example:
Na +1
11 p+
23-11 = 12no (Mass #- Atomic #)
11 – (+1) = 10 e- (atomic # - Charge)
*Since there are 11 p+ and 10 e-, there are more +’s than –‘s creating a + change
for the atom.
Example:
O-2
8 p+
16-8= 8 no
8 – (-2) = 10 e*Since there are 8 p+ and 10 e-, there are more –‘s than +’s creating a negative
charge.
Types of IONS
Cation
 Positive ion
 Loses electrons
Anion
 Negative ion
 Gains electrons
Valence Electrons
Valence Electrons: the number of electron in the outer energy level of an atom.
*We can figure this out by writing out the electron configuration for an element.
Example:
Na = 1s2 2s2 2p6 3s1
Add up the e-‘s found in the last energy level, in this case there is only 1 so Na has
1 valence e**You have to do this for the Transition metal every time**
*All the other element
will follow this trend