Question

If an atom has electronic configuration $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}4s^2$ it will be placed in?

• A. Second group
• B. Third group
• C. Fifth group
• D. Sixth group

Answer 1

The correct option is A

Second group

To find the group of the element always look at the last orbital and the number of electrons in it.

$1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}4s^2$ this element has 2 electrons in the outermost s-orbital.

So, it belongs to the s-block and also the 2nd group in the periodic table.