an atom has the electron configuration of $1s^{2}2s^{2}2p^{5}$. how man…

$an atom has the electron configuration of $1s^{2}2s^{2}2p^{5}$. how man…$

an atom has the electron configuration of $1s^{2}2s^{2}2p^{5}$. how many electrons are in that atom?
a eight
b six
c ten
d nine

In electron configuration $1s^{2}2s^{2}2p^{5}$, sum the exponents $2 + 2+5$.

$2+2 + 5=9$.

d. Nine