Question

an atom of an element has 3 electrons in the M-shell .What is the atomic no. of this element​

Answer 1

Answer

13

Explanation

by using formulae 2n² ( n= no. of shell)

K shell will have 2(1)²=2

L shell will have 2(2)²=8

and M shell have three electron so

Atomic mass will be 2+8+3=13

Answer 2

Explanation:

atomic no is thirteen because electronic configuration is k-2,L-8,m-3

therefore k+l+m+n= atomic number