Group 14

Question 1

Structure of C(diamond)

Answer 1

Giant covalent structure- strong directional bonding.

Hard insulating

Question 2

Structure of C(graphite)

Answer 2

Covalent- some electrical conductivity in plane

Question 3

Structure of Si and Ge

Answer 3

Diamond like structure. Semi conductors b/c intermediate electronegativity.

Question 4

Structure of Sn

Answer 4

Changes with temperature.
Cold- diamond structure-non metallic insulating
Warm- metallic conductor

Question 5

Why can carbon form both sigma and pi bonds

Answer 5

They aren’t that different in energy. So it can from both rather than just lots of sigma

Question 6

Why does silicon not have and pi bonds?

Answer 6

the sigma bonds are much stronger so it just isn’t favourable.

Question 7

Since there is sigma and pi bonding in CO2 what are the molecules like?

Answer 7

Discrete. Don’t catenate

Question 8

What is the inert pair effect and what does it explain?

Answer 8

It explains why there can be different oxidation states down a group.
Smaller elements can form really strong ionic lattices which would offset the cost of removing more electrons.
Also 6s electrons held really tightly in heavy elements so hard to remove them

Question 9

Why do not many elements form pi bonds?

Answer 9

As the elements get bigger overlap is much worse, this is dramatic for pi bonds as they are above the bond, so their overlap decreases at a much more rapid pace than sigma