Phosphorus has an atomic number of 15, so what is the distribution of its electrons?

Question

Quizplus · Accepted Answer

Phosphorus has 15 electrons. Following the Aufbau principle (filling orbitals in order of increasing energy), the first energy level can hold up to 2 electrons, the second energy level can hold up to 8 electrons, and the third energy level can hold up to 5 electrons. Therefore, the distribution of electrons in phosphorus is: 2 in the first energy level, 8 in the second energy level, and 5 in the third energy level. This corresponds to choice B.

Phosphorus Has an Atomic Number of 15, So What Is