For the electrons of oxygen atom, which of the following statements is correct?
(a) Zeff for an electron in a 2s orbital is the same as Zeff for an electron in a 2p
(b) An electron in the 2s orbital has the same energy as an electron in the 2p
(c) Zeff for an electron in Is orbital is the same as Zeff for an electron in a 2s orbital.
(d) The two electrons present in the 2s orbital have spin quantum numbers ms but of opposite sign.
The answer is the option (d)
The two electrons present in the 2s orbital have spin quantum numbers ms but of opposite sign. This is so because in the same orbital plane, only two electrons can exist, and they must have opposite signs.