What is the definition of ionisation energy?

What is the general equation for ionisation energy?

How are we able to measure ionisation energy?

What is the difference between ionisation energy and electron affinity?

What does the term successive ionisation energies mean?

What are the three factors we need to consider to explain trends in ionisation energies?

How does the size of the nuclear charge affect ionisation energy?

How does atomic radius affect ionisation energy?

How does electron shielding affect ionisation energy?

General trends down a group:
Ionisation energy levels decrease down a group.

General trends across a period:
Ionisation energy levels increase across a period