For the electrons of oxygen atom, which of the following statemetns correct?

Options

A. `Z_("eff")` for an electron in a 2s orbital is the same as `Z_("eff")` for an electron in a 2p orbital
B. An electron in the 2s orbital has the same energy as an electron in the 2p orbital
C. `Z_("eff")` for electron in 1s orbital is the same `Z_("eff")` for an electron in a 2s orbital
D. The two electrons present in the 2s orbital have spin quantum number `m_(s)` but of opposite sign

Answer

D

Explanation

Electrons in 2s and 2p orbitals have different screening effects. Hence, their `Z_("eff")` is different. Therefore, (a) is not correct. Energy of `2s lt 2p`. Hence, (b) is not correct. For reason similar to that of (a), (c) is also not correct. The two electrons in any orbital have spin quantum numbers with opposite sign. Hence, (d) is correct