Group 2

Question 1

why are group 2 elements described as s-block elements?

Answer 1

their highest energy electron occupies an s orbital

Question 2

whats the structure of group 2?

Answer 2

giant
metallic

Question 3

what are the physical properties of group 2 ?

Answer 3

-giant metallic
-good electrical conductors because they have mobile, delocalised electrons which can move an carry a charge
-high melting and boiling points
because a lot of energy is needed to break the strong metallic bonds

Question 4

describe the trend in atomic radii down the group

Answer 4

-more shells
-more shielding effect by inner shell electrons
-the increased distance of the outer electron from the nucleus and increased shielding effect far outweighs the increase in nuclear charge
-so nuclear attraction on the outer-shell electrons decrease down group 2
-so atomic radius increases

Question 5

what colour flame does magnesium burn with?

Answer 5

white flame

Question 6

what does group 2 elements react with to form metal hydroxides + hydrogen

Answer 6

cold water (room temp)

Question 7

what does the vigorous reaction of magnesium + steam make?

Answer 7

magnesium oxide + hydrogen

Question 8

why are the group 2 hydroxide solutions more alkaline down the group?

Answer 8

because solubility increases down the group

Question 9

explain why Ba(OH)2 has a greater pH than Ca(OH)2

Answer 9

Ba(OH)2 is more soluble than Ca(OH)2

Question 10

give one use and reason of Mg(OH)2

Answer 10

-used in some indigestion tablets as an antacid
-because it is mild alkali it neutralizes excess stomach acid safely

Question 11

give one use and reason of Ca(OH)2

Answer 11

-used in agriculture to neutralise acid soil

Question 12

group 2 metal carbonates decompose by heat to form what?

Answer 12

metal oxide + CO2

Question 13

why do group 2 carbonates become more difficult to decompose with heat down the group?

Answer 13

the thermal stability of carbonates increases down the
group