# What element has the electron configuration 1s^2 2s^2 2p^6 3s^2 3p^4?

$Z = 16$, therefore the element is silicon.
The neutral atom contains as many electrons, negatively charged particles, as positively charged particles, which reside in the nucleus. There are 16 electrons, and thus $Z$, the nuclear charge is necessarily $16$.
If $Z$ $=$ $16$, the element clearly silicon, $S i$. Capisce?