Question

The electronic configuration of an element is $1s^2,2s^2,2p^6,3s^{2}3p^3$. what is the atomic number (X) of the element which is just below the above given element in the periodic table. find the value of $X$.

Answer 1

The electronic configuration $1s^2,2s^2,2p^6,3s^{2}3p^3$ represents phosphorus with atomic number 15. Arsenic is just below phosphorus in the periodic table. Its atomic number is 33.