[3] Electronic structure and orbitals

What is an atomic orbital?

A region around the nucleus that can hold up to two electrons with opposite spins.

What is the maximum number of electrons in an orbital?

Two electrons with opposite spins.

What is the maximum electron capacity of the first four shells?

2, 8, 18 and 32 respectively.

What is an s orbital's shape?

Spherical.

What is a p orbital's shape?

Dumbbell-shaped.

How many s orbitals occur in each principal energy level?

One.

How many p orbitals occur in each principal energy level from n = 2?

Three.

What is the maximum electron capacity of an s subshell?

2 electrons.

What is the maximum electron of a p subshell

6 electrons

What is the maximum electron capacity of a d subshell

10 electrons.

What is the maximum electron capacity of an f subshell

14 electrons.

What does the Aufbau principle state?

Electrons occupy the lowest available energy orbitals first.

What does the Pauli exclusion principle state?

No two electrons in an atom can have the same four quantum numbers.

What does Hund's rule state?

Electrons occupy degenerate orbitals singly with parallel spins before pairing.

Why do electrons occupy degenerate orbitals singly before pairing?

This minimises electron-electron repulsion and produces a more stable arrangement.

Why does 4s fill before 3d?

The 4s orbital is lower in energy when these orbitals are initially filled.