Question

What are the electronic configurations for the first twenty elements

Answer 1

H   1s¹
He 1s²
Li    [He] 2s¹
Be  [He] 2s²
B    [He]2s²2p¹
C    [He]2s¹2p²
N   [He] 2s²2p³
O   [He]2s²2p⁴
F     [He]2s²2p⁵
Ne    [He]2s2p⁶
Na   [Ne]3s¹
Mg    [Ne]3s²
Al    [Ne]3s²3p¹
Si    [Ne]3s²3p²
P    [Ne]3s²3p³
S    [Ne]3s²3p⁴
Cl    [Ne]3s²3p⁵
Ar    [Ne]3s²3p⁶
K    [Ar]4s¹
Ca  [Ar]4s²