Covalent Bonds

Question 1

What are covalent bonds formed between

Answer 1

non-metals

Question 2

when are covalent bonds formed

Answer 2

Went to atoms need to gain the same amount of electrons to get a full outer shell
The two atoms share electrons but claim them as their own

Question 3

Give some examples of simple molecular substances

Answer 3

H2 (Hydrogen)
H2O (Water)
CH4 (Methane)
CO2 (Carbon dioxide)
O2 (oxygen)
HCl (hydrogen chloride)

Question 4

Give the properties of simple molecular substances

Answer 4

The atoms within the molecules are held together by strong covalent bonds
The forces of attraction between these molecules are very weak so the melting and boiling points are very low.
They don’t conduct electricity because they don’t contain any free electrons or ions

Question 5

Give some examples of giant covalent structures

Answer 5

Diamond
Graphite
Graphene

Question 6

What are the properties of giant covalent structures

Answer 6

All atoms are bonded to each other by strong covalent bonds
Very high melting and boiling points as lots of energy is needed to break the covalent bonds. Don’t conduct electricity as I don’t contain charge particles
They aren’t soluble in water

Question 7

How many covalent bonds are between each carbon atom in diamond

Answer 7

4

Question 8

What are the properties of diamond

Answer 8

🏮High melting point, the strong covalent bonds take lots of energy to break
🏮Really hard, the covalent bonds hold the atoms in a rigid lattice structure
🏮Does not conduct electricity, no free electrons or ions

Question 9

What is diamond used for

Answer 9

Used to strengthen cutting tools (e.g. saw teeth) because it is so strong

Question 10

How many covalent bonds are between each carbon atom in graphite

Answer 10

3 (This creates sheets of carbon atoms are arranged in hexagons)

Question 11

What are the properties of graphite

Answer 11

🏮Soft and slippery, the layers move over each other as there aren’t any covalent bonds between the layers.
🏮High melting point, lots of energy needed to break the covalent bonds.
🏮Can conduct electricity, only 3/4 outer electrons are used in bonds so each carbon atom has 1 electron that is free to move.

Question 12

What is buckminsterfullerene’s molecular formula

Answer 12

C6O

Question 13

What does C6O form

Answer 13

A hollow sphere made up of 20 hexagons and 12 pentagons

Question 14

What a nano tubes

Answer 14

Tiny cylinders of graphene

Question 15

What are the properties of graphene

Answer 15

Conduct electricity
they don’t break when stretched
they’re strong yet light

Question 16

What are nanotubes used for

Answer 16

Sports equipment, to strengthen it and remain light