Chem 9- Group 2

Question 1

What happens to the size of the atoms as you go down group 2 and why does it happen?

Answer 1

The atoms get bigger because the atomic radius increases because each element has an extra filled main level of electrons compared with the one above it

Question 2

What happens to the melting point going down group 2 and why?

Answer 2

It decreases because

• going down the group the electrons in ‘sea’ of delocalised electrons are further away from the positive nuclei
• strength of metallic bonds decrease going down the group

Question 3

What happens to the ionisation energy going down the group and why?

Answer 3

It decreases because :

• it takes less energy to remove electrons as they become further away from the nucleus
• theres more shielding

Question 4

How do group 2 elements react with water?

Answer 4

• more reactive going down the group

- Mg reacts slowly with cold water but rapidly with steam