# What element has the electron configuration 1s2 2s2 2p6 3s2 3p2?

May 26, 2014

The electron configuration $1 {s}^{2} 2 {s}^{2} 2 {p}^{6} 3 {s}^{2} 3 {p}^{2}$ is the element Silicon.

The key to deciphering this is to look at the last bit of information of the electron configuration $3 {p}^{2}$.

The '3' informs us that the element is in the 3rd Energy Level or row of the periodic table. The 'p' tells us that the element is found in the p-block which are all of the Groups to the right of the transition metals, columns 13-18. The superscript '2' tells us that the element is found in the 2nd column of the p-block Group 14.

SMARTERTEACHER

Oct 3, 2015

Silicon

#### Explanation:

The supercripts (2, 2, 6, 2 and 2) are the number of electrons in each orbital. Simply add up these numbers, which will give you 14.
Now just look for the element on the periodic table with the atomic number of 14.
This is because the atomic number tells you the number of protons, and the number of electrons is equal to that of the protons (unless the element has become an ion, of course, but since there is no information saying it is an ion, we'll assume it isn't).
So, the element with the atomic number of 14 is Silicon!