Covalent Substances

Question 0

What are the features of simple molecular substances?

Answer 0

They have low boiling and melting points because the bonds are easily seperated

Question 1

Describe the structure of a simple covalent substance?

Answer 1

They are molecular substances which are gas or liquids at room temperature
They have weak inter molecular bonds

Question 2

Describe the structure of giant covalent substances?

Answer 2

They are similar to an ionic lattice

All the atoms are bonded together by strong covalent bonds

Question 3

What are the features of giant covalent substances?

Answer 3

They have high boiling and melting points
They don’t conduct electricity except for graphite
They are usually insoluble in water

Question 4

Name two giant covalent substances?

Answer 4

Diamond and graphite

Question 5

Why is diamond a strong substance?

Answer 5

Each carbon atom forms 4 covalent bonds in a very rigid giant covalent structure

Question 6

Why doesn’t diamond conduct electricity?

Answer 6

There are no free electrons

Question 7

Why is graphite a good conductor of electricity?

Answer 7

As only 3 out of each carbon’s 4 electrons are used in bonds so there are lots of delocalised electrons that can move and carry an electric current

Question 8

Describe the structure of graphite?

Answer 8

Each carbon atom in graphite only forms 3 covalent bonds, which creates a sheet of carbon atoms that can easily slide over each other