Ionisation energy

Question 1

Define first ionisation energy

Answer 1

energy needed to remove 1 moles of the outermost electrons from 1 mole of gaseous atoms of an element to form 1 mole of its ions

Question 2

Whats the equation for first ionisation of lithium?

Answer 2

Li—-> Li+ + e-

Question 3

Define second ionisation energy

Answer 3

energy needed to remove a second electron from each ion in a mole of ions in a gaseous state

Question 4

Comment on the ionisations of calcium

Answer 4

as each e- is removed from an atom the ion is more +ively charged removing an e- from an increasing +ive charge is more difficult and the energy is larger

Question 5

What the equation for the second ionisation of calcium?

Answer 5

Ca+ ——> Mg2+ + e-

Question 6

What happens to ionisation down a group and across a period?

Answer 6

Increases across, decreases down

Question 7

Why does it decrease down?

Answer 7

Atomic radius further from nucleus, easier to remove - decreases
Nuclear charge increases as electrons harder to remove
Shielding decreases

Question 8

Why does it increase across?

Answer 8

Atomic radius decreases as e- closer to nucleus and harder to remove
Nuclear charge increases
Shielding the same as inner shells have the same electrons

Question 9

Define successive ionisation energy

Answer 9

Measure of energy required to remove each e- in turn

Question 10

Why do successive ionisation energies get larger?

Answer 10

as each e- is removed theres less repulsion between e- and eache shell will be drown closer to nucleus
e- closer to nucleus increasing attraction