Which of the following statement (s) is (are) correct?

Options

A. The electronic configuration of Cr is `[Ar]3d^(5)4s^(1)` (atomic number of `Cr=24`)
B. The magnetic quantum number may have a negative value
C. In silver atom, 23 electrons have a spin of one type and 24 of the opposite type. (atomic number of `Ar=47`)
D. The oxidation state of nitrogen in `NH_(3)` is `+3`

Answer

A, B, C

Explanation

(a) `Cr=[Ar]3d^(5)4s^(1)`, an exception to Aufbau principle.
(b) For a given value of l, m can have any value from `(-l" to "+ l)`, so can have negative value.
(c) Ag is in copper group with `d^(10)s^(1)` configuration, i.e. 46 electrons are spin paired.