How many valence electrons are there in 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p2 ?

Answer:

The element with the electron configuration of 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p2 has four valence electrons.But it has totally 32 electrons.

Explanation:

Given, 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p2

At first,find out the Valence shell.Here, the fourth shell is the valence shell 4s24p2.We know that the electrons in valence shell are called valence electrons.Here we get four valence electrons in 4s24p2.That is why the element with the electron configuration of 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p2 has four valence electrons.

Remember that the electrons in fullfiled d orbital are not counted as valence electrons.A d orbital can hold maximum 10 electrons.