Question

what element is represented by the electron configuration below? 1s² 2s² 2p⁶ 3s² 3p³
phosphorus
lithium
arsenic

Explanation:

To determine the element from an electron - configuration, sum the electrons. The sum of electrons in the given configuration \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{3}\) is \(2 + 2+6 + 2+3=15\). Phosphorus has an atomic number of 15, which means it has 15 electrons. Lithium has 3 electrons and arsenic has 33 electrons.

Answer:

phosphorus