ionisation energy

What is electron shielding?

Electron shielding (or screening) is the repulsion between electrons in different shells, where inner shell electrons repel outer shell electrons.

Define molar first ionisation energy.

The molar first ionisation energy of an element is the energy required to remove one mole of electrons from one mole of its gaseous atoms.

What is standard ionisation energy?

The standard ionisation energy occurs under the conditions of 298K and 1 atm.

Explain the factors that affect ionisation energy.

Ionisation energy is affected by: Nuclear charge (greater nuclear charge increases attraction), Electron shielding (more inner shells reduce attraction), Atomic radius (greater radius decreases attraction).

Write the equation for the first ionisation energy of an element X.

The first ionisation energy of an element X is summarized by the equation: X(g) → X+(g) + e.

Describe the general trend in ionisation energy across a period.

Ionisation energy generally increases across a period due to increasing nuclear charge and decreasing atomic radius.

Describe the trend in ionisation energy down a group.

Ionisation energy generally decreases down a group due to increased electron shielding and larger atomic radius.

Write an equation for the second ionisation energy of magnesium.

The second ionisation energy of magnesium is represented as: Mg+(g) → Mg2+(g) + e.

How does the first ionisation energy of He compare to Ne?

He > Ne because neon's outer electron experiences increased shielding from inner electrons and is further from the nucleus.

Why does B > Be in ionisation energy?

B > Be because boron's outer electron is in a new sub-shell, which is further from the nucleus and partly shielded by the 2s electrons.

Why does n have a high first ionisation energy than o

Since the electron-electron repulsion between two paired electrons in one p orbital in oxygen makes one of the electrons easier to remove nitrogen does not contain paired electron