4.1 Covalent Bonds

Question 1

What is a Covalent Bond?

Answer 1

An electrostatic force of attraction between a nuclei and a shared pair of electrons.

Question 2

What is a molecule?

Answer 2

A group of atoms joined by covalent bonds.

Question 3

Why do simple molecular substances have low melting/boiling points?

Answer 3

Due to weak intermolecular forces which can easily be broken with little energy.

Question 4

Why don’t simple molecular substances conduct electricity?

Answer 4

Molecules are free to move but are neutrally charged and can’t conduct.

Question 5

What type of structure and bonding do metals have?

Answer 5

Bonding - Metallic
Structure - Giant Metallic

Question 6

Do metals have a high or low melting point and can they conduct electricity?

Answer 6

Can conduct electricity
High melting point

Question 7

What type of structure and bonding do metals and non-metals have?

Answer 7

Bonding - Ionic
Structure - Giant Ionic

Question 8

Do metals and non-metals have a high or low melting point and can they conduct electricity?

Answer 8

Can only conduct electricity when liquid
High melting point

Question 9

What type of structure and bonding do non-metals have?

Answer 9

Bonding - Covalent
Structure - Simple Molecular

Question 10

Do non-metals have a high or low melting point and can they conduct electricity?

Answer 10

Can’t conduct electricity
Low melting point

Question 11

What type of structure and bonding do Grp 4 elements have?

Answer 11

Bonding - Covalent
Structure - Giant Covalant

Question 12

Do Grp 4 elements have a high or low melting point and can they conduct electricity?

Answer 12

Can sometimes conduct electricity
Very High Melting point

Question 13

What type of structure is C60 Fullerene?

Answer 13

Simple molecular

Question 14

Can C60 Fullerene conduct electricity?

Answer 14

No - neutral molecules

Question 15

Give key information on C60 Fullerene? (In terms of bonding and molecular substance)

Answer 15

C60 Fullerene has a high molecular substance.
It has fairly strong intermolecular forces which are difficult to break

Question 16

Is C60 Fullerene soft and slippery, if so why?

Answer 16

Yes - weak forces between molecules allow molecules to roll over eachother

Question 17

What type of shape is the diamond structure?

Answer 17

Tetrahedral Shape

Question 18

What is diamond used for?

Answer 18

Cutting things

Question 19

How many bonds are there between carbon atoms in a diamond?

Answer 19

4 bonds

Question 20

How is a diamond hard?

Answer 20

All atoms are fixed in position

Question 21

Can diamond conduct electricity?

Answer 21

No

Question 22

What type of shape is graphite?

Answer 22

hexagonal

Question 23

How many bonds are there between carbon atoms in a graphite?

Answer 23

3 bonds

Question 24

What is graphite used for?

Answer 24

Solid Lubricant

Question 25

Can graphite conduct electricity?

Answer 25

Yes it has one free electron which is free to move as it's not used in covalent bonds

Question 26

What type of bonding does graphite have?

Answer 26

Weak intermolecular forces meaning layers of sheets can slide over each other easily and break apart

Question 27

Does Silicon Dioxide have a high or low melting point?

Answer 27

Very High

Question 28

What structure is Silicon Dioxide?

Answer 28

Giant covalent meaning it requires high amount of energy to break

Question 29

Does Silicon Dioxide conduct electricity?

Answer 29

No - no free moving delocalised electrons