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