group # = # valence (outside) e-
1A
1
2A
8A
3A 4A 5A 6A 7A
2
Row 3
=
4
# shells
5
6
3B 4B 5B 6B 7B 8B 8B 8B 1B 2B
s
d
p
7
6
7
f
Electron Configuration
1
1s
group #
row #
# valence eshell #
possibilities are:
possibilities are 1-7
s: 1 or 2
7 rows
subshell
p: 1-6
possibilities are
d: 1-10
s, p, d, or f
f: 1-14
4 subshells Total e- should equal
Atomic #
What element has an electron configuration of 1s1?
Practice:
Ask these questions every time you have to write an
electron configuration
•
Lithium:
1.
2.
3.
4.
5.
6.
7.
find the element on the periodic table atomic # = 3
what is the period number? 2
how many shells? 2
what is the group number? 1
how many valence electrons? 1
what subshell(s) does Li have? s
what is the electron configuration? 1s2 2s1
Practice:
Ask these questions every time you have to write an
electron configuration
•
Boron:
1.
2.
3.
4.
5.
6.
7.
find the element on the periodic table atomic # = 5
what is the row #? 2
how many shells? 2
what is the group #? 3
how many valence electrons? 3
what subshell(s) does B have? p
what is the electron configuration? 1s2 2s2 2p1
Order of Electron Subshell Filling:
It does not go “in order”
1s2
2s2 2p6
3s2 3p6 3d10
4s2 4p6 4d10 4f14
5s2 5p6 5d10 5f14
6s2 6p6 6d10
7s2 7p6
1s2 2s2 2p6 3s2 3p64s2 3d10 4p65s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d10 7p6
Subshells d and f are “special”
group # = # valence e-
1A
period # = # e- shells
1
2A
3A 4A 5A 6A 7A
2
3
3B 4B 5B 6B 7B 8B 8B 8B 1B 2B
4
6
3d
4d
5d
7
6d
5
8A
d
6 4f
7 5f
f
Electron Configuration
1
1s
group #
row #
# valence eshell #
possibilities are:
possibilities are 1-7
s: 1 or 2
7 rows
subshell
p: 1-6
possibilities are
d: 1-10
s, p, d, or f
f: 1-14
4 subshells Total e- should equal
Atomic #
What element has an electron configuration of 1s1?
Practice:
Ask these questions every time you have to write an
electron configuration
•
Lithium:
1.
2.
3.
4.
5.
6.
7.
find the element on the periodic table
what is the row #?
how many shells?
what is the group #?
how many valence electrons?
what subshell(s) does Li have?
what is the electron configuration?
Practice:
Ask these questions every time you have to write an
electron configuration
•
Boron:
1.
2.
3.
4.
5.
6.
7.
find the element on the periodic table
what is the row #?
how many shells?
what is the group #?
how many valence electrons?
what subshell(s) does B have?
what is the electron configuration?
Order of Electron Subshell Filling:
It does not go “in order”
1s2
2s2 2p6
3s2 3p6 3d10
4s2 4p6 4d10 4f14
5s2 5p6 5d10 5f14
6s2 6p6 6d10
7s2 7p6