Assuming aufbau principle, what is the number of electrons in an atom in which the 4p electron is fully filled?
A) 8
B) 10
C) 18
D) 28
E) 36

Question

Quizplus · Accepted Answer

The aufbau principle states that electrons fill atomic orbitals of the lowest available energy levels before occupying higher levels. For the 4p subshell to be fully filled, it must contain its maximum of 6 electrons. Before reaching the 4p subshell, electrons would fill the 1s, 2s, 2p, 3s, 3p, 4s, and 3d subshells. Adding up the electrons in these subshells (2 in 1s, 2 in 2s, 6 in 2p, 2 in 3s, 6 in 3p, 2 in 4s, and 10 in 3d) plus the 6 in the 4p subshell gives a total of 36 electrons.

Assuming Aufbau Principle, What Is the Number of Electrons in an Atom