Suppose that the electron spin quantum number could have three possible values. Then which of the following atomic number would not represent a noble gas.

Options

A. 3
B. 15
C. 27
D. 42

Answer

D

Explanation

Possible configurations and atomic numbers of noble gases would be (when each orbital would have 3 electrons)
`He=1s^(2)(Z=3)`
`Ne=1s^(1)2s^(1)2p^(9) (Z=15)`
`Ar=1s^(1)2p^(9) 3s^(1) 3p^(9) (Z=27)`
`Kr=1s^(1)2s^(1)3s^(1)3p^(9)4s^(1)3d^(15)4p^(9) (Z=54)`
Thus, `Z=42` will not represent a noble gas.