Question

An element has an atomic number 12. How many electrons will be present in the K, L and M energy shells of its atom?

Answer 1

Electronic configuration of element with atomic number 12 is:

$\underset{2}{\mathrm{K}}\underset{8}{\mathrm{L}}\underset{2}{\mathrm{M}}$

There will be 2 electrons in the K shell, 8 electrons in the L shell and 2 electrons in the M shell of its atom.