Group 2,7

Question 1

Describe what happens to the atomic radius as you go down group 2

Answer 1

Increases, because there are more electron shells

Question 2

Describe what happens to the ionisation energy as you go down group 2

Answer 2

Decreases, because the atomic radius increases, because there are more electron shells, so there is a greater distance between the outer electron and nucleus, so there is a weaker attraction, so less energy is required to overcome these forces of attraction and remove an electron.

Question 3

Describe what happens to the melting point as you go down group 2

Answer 3

Decreases, because the ionic radius increases, so there is a greater distance between the delocalised electrons and nucleus, so the strength of the metallic bonds decreases

Question 4

Which element in group 2 deviates the trend in melting point

Answer 4

Magnesium

Question 5

Magnesium can be used to extract titanium from its ore.

Answer 5

TiO2 (s) + 2Cl2 (g) + 2C (s) → TiCl4 (1) + 2CO (g)

TiCl4 (l) + 2Mg (s) → Ti (s) + 2MgCl2 (s)

Question 6

Describe the use of calcium compounds

Answer 6

Calcium compounds can be used to remove the sulfur dioxide that is released in fossil fuel emission, before it turns into acid rain.
CaCO3 (s) + SO2 (g) → CaSO3 (s) + CO2 (g)

Question 7

How are hydroxides formed

Answer 7

When Group2elements react with water

Question 8

What happens to the solubility of Group2hydroxides as you go down the group

Answer 8

The solubility of Group2hydroxides increases as we go down the group.

Question 9

Magnesium reacts with water

Answer 9

Mg (s) + 2H2O (1) → Mg(OH), (aq) + H2 (g)

Question 10

Magnesium reacts with steam

Answer 10

Mg (s) + H2O (g) → MgO (s) + H2(g)

Question 11

Describe the use of magnesium hydroxide

Answer 11

Magnesium hydroxide is often used to cure acid reflux, or heartburn.

Question 12

Explain why magnesium hydroxide is effective

Answer 12

it’s a strong enough base to neutralise the excess stomach acid, but not strong enough to cause any damage to the body.

Question 13

Describe what happens to the solubility of group 2 sulfates as you go down the group

Answer 13

Decreases

Question 14

Describe the use of barium sulfate

Answer 14

Barium meal in x-rays

Question 15

State basic properties of group 7 elements

Answer 15

• Very reactive non-metals
• Diatomic
• Halogens

Question 16

What do halogens form when they gain an electron

Answer 16

Halides

Question 17

Describe Flourine at room temperature

Answer 17

Pale yellow gas

Question 18

Describe Chlorine at room temperature

Answer 18

Greenish gas

Question 19

Describe bromine at room temperature

Answer 19

Brown liquid

Question 20

Describe iodine at room temperature

Answer 20

Dark grey solid

Question 21

Describe the trend in electronegativity as you go down group 7

Answer 21

Decreases

Question 22

Describe the trend in melting/boiling point as you go down group 7

Answer 22

Increases, elements have more electrons, stronger Van der Waals forces, requires a great deal of energy to overcome

Question 23

Describe the trend in oxidising power of halogens as you go down group 7

Answer 23

Decreases

Question 24

Describe the trend in reducing power of halides as you go down the group

Answer 24

Increases