Question

If two electrons are already placed in the 1s sublevel, the next sublevel that would be used to hold an electron is the 2s sublevel and not the 2p sublevel. This is an example ofA. the Aufbau PrincipleB. the Pauli Exclusion PrincipleC. Hund's RuleD. Electron Configuration Principle

Answer 1

The correct answer is the Aufbau Principle, which dictates that electrons fill the lowest available energy levels first, so after the 1s sublevel is filled, electrons then fill the 2s sublevel.

Step-by-step explanation:

If two electrons are already placed in the 1s sublevel, the next sublevel that would be used to hold an electron is the 2s sublevel and not the 2p sublevel. This is an example of the Aufbau Principle. The Aufbau Principle states that electrons fill the lowest available energy levels before filling higher ones. As per the principle, after the 1s sublevel is filled, the next electron would enter the 2s sublevel because it's the next lowest energy sublevel available.

Other principles that are integral to understanding electronic configuration include the Pauli Exclusion Principle, which states that no two electrons can have the same set of four quantum numbers within an atom, meaning an orbital can contain a maximum of two electrons with opposite spins. Additionally, Hund's Rule indicates that electrons will singly occupy equal energy orbitals before pairing up.