In the simplified electron configuration notation, what is the electron configuration for a phosphorus atom (P), which has 15 electrons?

• A. $1s^{2}2s^{2}2p^{6}3s^{2}3p^5$
• B. $1s^{2}2s^{2}2p^{6}3s^{2}3p^3$
• C. $s^2{p}^3$
• D. $1s^{2}2s^{2}2p^{6}3s^{1}3p^4$

Answer: (B)