Ionisation Energy

Question 1

Define first ionisation energy

Answer 1

The energy required to remove the electrons from each atom of 1 mole of gaseous atoms of an element in order to form 1 mole of gaseous 1+ ions

Question 2

The lower the ionisation energy, the ______ it is to lose electrons

Answer 2

Easier

Question 3

Ionisation Energy Equation

Answer 3

X(g) —> X-(g) + e-

Question 4

Successive ionisation energies from the same shell require

Answer 4

more energy

Question 5

3 Factors affecting ionisation

Answer 5

Atomic radii, electron shielding and nuclear charge

Question 6

TREND DOWN A GROUP

Answer 6

Ionisation energy decreases

Question 7

TREND ACROSS A PERIOD

Answer 7

Generally increases; with some anomalies

Question 8

Anomalies across a period (where ionisation energy decreases)

Answer 8

Group 2 to Group 3 and Group 5 to 6

Question 9

Oxygen has a lower ionisation energy than _____

Answer 9

Nitrogen

Question 10

Boron has a lower ionisation energy than ______

Answer 10

Beryllium

Question 11

Why does Boron have a lower ionisation energy than Beryllium?

Answer 11

Boron’s outer electron is removed from the 2p sub shell, whereas Beryllium’s is from the 2s sub shell. As Boron’s outer electron is further away from the nucleus there is less nuclear attraction.

Question 12

Across a period nuclear charge

Answer 12

Increases as the proton number increases

Question 13

Across a period electron shielding

Answer 13

Remains the same as they have the same number of shells

Question 14

Across a period atomic radius

Answer 14

Decreases, as electron shells are drawn closer to the nucleus due to the increasing nuclear charge.

Question 15

Down a group electron shielding

Answer 15

Increases

Question 16

Down a group nuclear charge

Answer 16

Increases; but this may be outweighed by electron shielding and atomic radius

Question 17

Down a group atomic radius

Answer 17

Increases