Question

Which set of quantum numbers represents the 19th electron in chromium?

Answer 1

The atomic no. of Cr is 24. It's electronic configuration can be written as:
1s​22p63s23p64s1
19th electron will reside in 4s orbital.
So the quantam numbers can be given as:
n=4, l=0(s), m=0, s=(+1/2)upward spin

Answer 2

The quantum numbers for the 19th19thelectron of Cr (Z = 24) are - (A)n=3,l=0,m=0,s=+12(B)n=4,l=0,m=0,s=+12(C)n=3,l=2,m=2,s=+12(D)n=4,l=2,m=2,s=+12