Which of the following is true ?

Options

A. The outer electronic configuration of the ground state chromium atom is `3d^(4)4s^(2)`
B. Gamma rays are electroomagnetic radiations of wavelength of `10^(-6) cm"to" 10^(-5) cm `
C. The energy of the electron in the `3d` orbital is less than that in the `4s` orbital of a hydrogen atom
D. The electron density in the xy plane in `3d_(s^(2) - y^(2)` orbital is zero

Answer

C

Explanation

a. The configuration is `3d^(5) 4s&^(2)`
b The wavelength atom , the enrgy of an order of ` 10^(-11) m `
c. In hydrogen atom , the energy of an el,ectron depends only on the principle quantum number of the orbitals which it occupes
d. In xz plane is not electron density if an electron occupies `3d_(x^(2) - y^(2)` orbital