Answer: A
Explanation:
As per Bohr model, the shells from innermost to outermost are filled in the order: 2, 8, 8, and so on (that's a bit more advanced level). The inner shells, which are closest to the nucleus, are filled first.
Hence, the inner shell has space for two electrons only. It cannot occupy 3 or 4 electrons.
Innermost shell = 2 electrons
Now, carbon has six electrons in total. So, 6-2 = 4 electrons are left.
The rest four electrons will go in the 2nd shell which can occupy maximum 8 electrons.
So, 2nd shell = 4 electrons
=> Electronic configuration of Carbon: 2, 4
