Question

1s2 2s2 2p6 3s2 3p6 3d5 4s2
which are the shells present in an atom of element x, having electrons?

Answer 1

Answer:

Explanation:

Total number of electrons are 12 and also we know that the atom is neutral unless it has some net charge. Here,we will consider that the atom is electrically neutral. So, total number of protons will also be 12.

The number of protons = Atomic number

So, the atomic number is 12 and the element name is Magnesium.

There are 3 shells present in this atom as the highest value of principal quantum number is 3. The principal quantum number tells us about the no. Of shells.