Electron shells and atomic orbitals

equal energy

When all ________ sub- shells contain one electron they pair up with another electron with an opposite spin.

energy level

The ________ is determined by the principal quantum number (n)

S orbitals

________ can hold 2 electrons.

s orbital

All shells contain a(n) ________.

p orbitals

There are three ________ px, py and pz.

Electrons

________ orbit the nucleus in energy levels or electron shells.