3.2.2 Group 2, the alkaline earth metals

Question 1

describe the trend in atomic radius as you go down group 2

Answer 1

increases
this is because extra electron shells are added as you go down

Question 2

describe the trend in first ionisation energy down group 2

Answer 2

decreases down the group
shielding effect increases meaning electrons are further away from the nucleus which reduces the attraction

Question 3

explain the melting point of the elements in terms of their structure and bonding

Answer 3

melting point decreases down the group
typically have metallic structures
going down the group, the metal ions get bigger increases ionic radius
increased distance between positive nuclei and delocalised electrons

Question 4

explain the reactions of the group 2 elements with water

Answer 4

react with water to give a metal hydroxide and hydrogen
react more readily down the group because ionisation energies decrease

Question 5

outline how magnesium is used in the extraction of titanium, include an equation

Answer 5

TiCl4 + 2Mg — Ti + 2MgCl