| Period | Group | |
|---|---|---|
| 1 ▶ | ||
| 1 |
1
H
Hydrogen
1s1
|
|
| 2 |
3
Li
Lithium
[He] 2s1
|
|
| 3 |
11
Na
Sodium
[Ne] 3s1
|
|
| 4 |
19
K
Potassium
[Ar] 4s1
|
|
| 5 |
37
Rb
Rubidium
[Kr] 5s1
|
|
| 6 |
55
Cs
Cesium
[Xe] 6s1
|
|
| 7 |
87
Fr
Francium
[Rn] 7s1
|
Tip: Hover over an element to compare its electron configuration to that of the element below it.