H1B - Trends in the Periodic Table

Question 1

Define the covalent radius

Answer 1

Half-the distance between two bonded atoms

Question 2

Define the 1st ionisation energy

Answer 2

Energy required to remove one mole of electrons from one mole of gaseous atoms

Question 3

Define electronegativity

Answer 3

This is a measure of the attraction an atom of an element has for bonding electrons

Question 4

What trends are displayed by the covalent radius?

Answer 4

The covalent radius increases going down the group and decreases going across the period

Question 5

Justify the trend seen in the covalent radius going down the group

Answer 5

It increases due to the increasing number of electron shells making the atom bigger

Question 6

Justify the trend seen in the covalent radius going across the period

Answer 6

It decreases due to the increasing nuclear charge pulling the electrons closer to the nucleus

Question 7

What trends are displayed by the 1st ionisation energy?

Answer 7

The 1st ionisation energy decreases going down the group and increases going across the period

Question 8

Justify the trend seen in the 1st ionisation energy going down the group

Answer 8

It decreases due to the increasing number of electron shells making the atom bigger and increased shielding as this means that the outer electrons are less strongly held

Question 9

Justify the trend seen in the 1st ionisation energy going across the period

Answer 9

It increases due to the increasing nuclear charge pulling electrons closer to the nucleus and the smaller covalent radius meaning the outer electrons are more strongly held

Question 10

What trends are displayed by electronegativity?

Answer 10

Electronegativity decreases going down the group and increases going across the period

Question 11

Justify the trend seen in electronegativity going down the group

Answer 11

It decreases due to the increasing number of electron shells making the atom bigger and the increased shielding resulting in the outer electrons being less tightly held

Question 12

Justify the trend seen in electronegativity going across the period

Answer 12

It increases due to the increasing nuclear charge pulling the electrons closer in to the nucleus and the smaller covalent radius meaning that the outer electrons are more tightly held