Group 2

Question 1

Trend in atomic radius down the group

Answer 1

Increases

1) Atoms have more shells of electrons down the group
2) So more shielding
3) Increasing atomic radii

Question 2

Trend in melting points down the group

Answer 2

Decreases

1) Metallic bonding weakens as atomic size increases

2) As distance between + ions and delocalised electrons increase

3) So electrostatic forces between + ions and delocalised electrons weaken

Question 3

Trend in first ionisation energy down group 2

Answer 3

Decreases

1) Outer electrons held more weakly as they’re held successively further from nucleus in additional shells

2) Outer electrons also become more shielded from attraction of the nucleus

Question 4

Trend in reactivity going down group 2

Answer 4

Increases

Question 5

Reaction between magnesium and oxygen

Answer 5

2Mg (s) + O2 (g) –> 2MgO (s)

Question 6

2 observations from reaction between magnesium and oxygen

Answer 6

Bright white flame

Solid white powder formed

Question 7

Magnesium reacting with water

Answer 7

Mg (s) + 2H2O (l) –> Mg(OH)2 (s) + H2 (g)

Question 8

Magnesium with steam (include the observations)

Answer 8

Mg (s) + H2O (g) –> MgO (s) + H2 (g)

Bright white flame
Solid white powder formed

Question 9

Reaction between Ca, Sr, Ba with water

Answer 9

Ca (s) + 2H2O (l) –> Ca(OH)2 (aq) + H2(g)

Sr (s) + 2H2O (l) –> Sr(OH)2 (aq) + H2(g)

Ba (s) + 2H2O (l) –> Ba(OH)2 (aq) + H2 (g)

Question 10

What would you observe for group 2 metals reacting with water as you go down the group?

Answer 10

1) More vigorous fizzing

2) Faster dissolving of the metal

3) Solution heating up more

4) Less ppt forming