Question

what is the electronic configuration of chromium

Answer 1

See in this pic
Ar
atomic number 18
E. C = 1s2 2s2 2p6 3s2 3p6
in the configuration of Chromium 4s is used because from this block it is, used this...

hopes helps u dearr

Answer 2

The electronic configuration of chromium is
$1s {}^{2} 2s {}^{2}2p {}^{6}3s {}^{2} 3p {}^{6}4s {}^{1}3d {}^{5}$