Group 2 -Alkaline Metals

Question 1

What happens to the atomic radius as you go down the group?

Answer 1

It increases due to more electron shells

Question 2

What happens to the first ionisation energy as you go down group 2

Answer 2

It decreases due to extra inner shells shield te outer electrons from attraction of the nucleus. Also the outer electron is further away from the nucleus which reduces the nucleus’s attraction.

Question 3

What happens to the reactivity as you go down group 2?

Answer 3

Reactivity increases. They lose electrons forming possitive ions when they react. The easier it is to lose the electrons the more reactive it is so reactivity increases down the group as the electrons become easier to lose

Question 4

What’s the general trend with melting points as you go down group 2 ? And why?

Answer 4

The melting points decrease. As you go down the group metal ions become bigger but the number of delocalised electrons doesn’t change and neither does the charge on the ion. The larger the ionic radius the further away the delocalised electrons are from the positive nuclei and less attraction they feel. So it takes less energy to break the bonds so melting point decrease generally as you go down the group.

Question 5

Why is there a blip in the trend with magnesium in melting points of group 2 elements?

Answer 5

Due to the crystal structure ( the arrangement of the metallic ions) changes

Question 6

When group 2 elements react with water what happens to them?

Answer 6

They are oxidised. They go from 0 to +2

Question 7

When group 2 elements react with water what are the products?

Answer 7

Metal hydroxide and hydrogen

Question 8

Why do group 2 elements react more readily with water as you go down the group?

Answer 8

This is because the ionisation energies decrease