Why are p-orbitals called degenerate orbitals?
Electron orbitals that have the same energy level are said to be degenerate orbitals. Since p orbitals have an azimuthal quantum number of 1, this means that there are three different p orbitals available for electrons (-1,0,+1). These three p orbitals are degenerate, meaning they all have exactly the same energy value. This is important to know when assigning electrons to orbitals because the p orbitals are all filled completely with a total of 6 electrons before moving on to higher energy orbitals. The filling up of electron orbitals from lowest energy to highest energy is the reasoning behind the Aufbau principle.