5x7=35, then 3-1=2, so 35+2=37
You can tell the difference between 1s subshell and 3s subshell using quantum numbers and electron configuration.
It's in the tables of 1s, 3s, 9s, and 27s .
The 1s, 2s, 2p and 3s
4s 3p 3s 2p 1s This is probably one of the easiest chemistry problems in the book, you should probably look it up.
1s^2 2s^2 2p^6 3s^2
1s^2 2s^2 2p^6 3s^2 3p^2
Sodium.
1s 2s 3s 3p 4s 3d 4p
1s 2s 2p 3s 3p 4s 3d 2p
Sodium has 3 energy levels, 1s, 2s, 2p, and 3s.
Its energy level must be increased.
1s^2 2s^2 2p^6 3s^2 3p^2