Question

The Aufbau Principle describes that

O electrons with the same spin cannot occupy the same orbital.
electrons will occupy single orbitals within and energy level before doubling up
electrons fill lower energy levels first before occupying higher energy levels.
O electrons in the same level have the same amount of energy

Answer 1

electrons fill lower energy levels first before occupying higher energy levels.

Step-by-step explanation:

The Aufbau's principle describes that electrons fill lower energy levels first before occupying higher energy levels.

In writing the electronic configuration of atoms, the Aufbau's principle is one of the most important principles to consider.

It states that "sublevels with with lower energies are filled up before those with higher energies".

Sublevels do not fill up in numerical order.