Question

Hydrogen electron is excited from the $1^{st}$ shell to the $2^{nd}$ shell. The maximum number of possibilities that the electron is present with different spin values, and with different orientations of the orbitals:

• A. 1
• B. 2
• C. 4
• D. 8

Answer 1

Answer: (C)

4

Hydrogen electron is excited from the $1^{st}$ shell to the $2^{nd}$ shell i.e., from $K$ shell to $L$ shell. The $K$ shell contains only $1s$ subshell and $L$ shell which contains $2s$ and $2p$ subshells. This excitation is shown in figure. From figure it is seen that maximum number of possibilities that the electron is present with different spin values, and with different orientations of the orbitals is 4.

$\underset{–}{\uparrow \downarrow \uparrow \downarrow \uparrow \downarrow \uparrow \downarrow }$ $\underset{–}{\uparrow \downarrow }$

$2s$ $2p$ $1s$