2.12 & 2.13

2.12 What is an s orbital?

A spherical region around the nucleus where an electron is likely to be found

2.12 What is the shape of a p orbital?

A dumbbell shape with two lobes

2.12 How many orbitals are in an s subshell?

1

2.12 How many orbitals are in a p subshell?

3

2.12 How many orbitals are in a d subshell?

5

2.13 How many electrons can one orbital hold?

A maximum of two electrons

2.13 What must be true of two electrons in the same orbital?

They must have opposite spins

2.13 What is the Aufbau principle?

Electrons occupy lower-energy orbitals before higher-energy orbitals

2.13 What is Hund's rule?

Orbitals of equal energy fill singly before electrons pair

2.13 Why do electrons occupy separate equal-energy orbitals before pairing?

This minimises electron-electron repulsion