Question

What are the four quantum numbers for the 3rd electron in xenon?

Answer 1

Ground state electronic configuration of Xenon (`Z = 54`) is

`1s^2 color(white)(.) 2s^2 color(white)(.) 2p^6 color(white)(.) 3s^2 color(white)(.) 3p^6 color(white)(.) 4s^2 color(white)(.) 3d^10 color(white)(.) 4s^2 color(white)(.) 4p^6 color(white)(.) 4d^10 color(white)(.) 5s^2 color(white)(.) 5p^6`

Third electron belongs to `2s` sub level.

So, the four quantum numbers of third electron are

• `n = 2` - because it belongs to 2nd shell

• `l = 0` - because it belongs to 2s sublevel

• `m = 0` - because it belongs to s orbital

• `m_s = 1/2` - because it’s the first electron in the orbital