Topic 2 Structure and Bonding

Question 1

What is solid to liquid ?

Answer 1

Melting

Question 2

What is liquid to solid

Answer 2

Freezing

Question 3

What is liquid to gas

Answer 3

Boiling

Question 4

What is gas to liquid

Answer 4

Condensing

Question 5

What is ionic bonding ?

Answer 5

When a metal reacts with a non-metal

Question 6

Why do elements react ?

Answer 6

To recieve a full outer energy level

Question 7

What does ionic bonding produce?

Answer 7

Ions = atoms with a overall charge

Question 8

What is formed when a metal and non-metal react?

Answer 8

Ionic compound

Question 9

What do group 1 metals and group 7 non-metals do to gain a full outer energy level

Answer 9

Group 1 metals lose one electron forming a one positive ion
Group 7 non-metals gain one electron forming a one negative ion

Question 10

What do group 2 metals and group 6 non-metals do to gain a full outer energy level

Answer 10

Group 2 metals lose two electrons forming a one 2 positive ion (2+)
Group 6 metals gain two electrons forming a 2 negative ion (2-)

Question 11

What do ionic compounds form?

Answer 11

Giant structures known as a giant ionic lattice (3d structure)

Question 12

What are the properties of ionic compounds?

Answer 12

• Have very high melting and boiling point - because of the strong electrostatic forces of attraction require a great deal of heat energy to break
• cannot conduct electricity when a solid. But can when melted or dissolved in water
• when ionic compounds conduct electrcity its the ions that are moving not the electrons

Question 13

What is single covalent bonding ?

Answer 13

1 shared pair of electrons

Question 14

What is double covalent bonding ?

Answer 14

Two shared pairs of electrons

Question 15

What is triple covalent bonding

Answer 15

Three shared pairs of electrons

Question 16

What is the aim of covalent bonding ?

Answer 16

To reach a full outer energy level

Question 17

What are the 3 ways of showing a covalent bond ?

Answer 17

Energy level diagram
Dot and cross diagram
Stick diagram

Question 18

What are the properties of small covalent molecules

Answer 18

• low melting and boiling points - because of their weak intermolecular forces
• the intermolecular forces in small covalent molecules are very weak and dont need a lot of energy to break
  -usually gases or liquids at room temperature
• covalent bonds are not broken down when a substance melt or boils
• as we increase the size of the covalent nolecule the intermolecular forces increases
• do not conduct electricity as dont have an overall charge

Question 19

What do giant covalent substances contain ?

Answer 19

Millions of covalent bonds

Question 20

What are giant covalent substances at room temperature ?

Answer 20

Solids because of high melting and boiling points

Question 21

Why do giant covalent substances have high melting and boiling points ?

Answer 21

Because they have millions of giant covalent bonds and require a great deal of energy to break

Question 22

What is diamond formed from ?

Answer 22

The element carbon
- diamond contains a huge number of carbon atoms joined by covalent bonds

Question 23

What are the properties of Diamond ?

Answer 23

• high melting and boiling point
• cannot conduct electricity

Question 24

What is silicon dioxide ?

Answer 24

A giant covalent molecule with a huge number of covalent bonds

Contains the elements silicon and oxygen covalently bonded together

Question 25

Property of silicon dioxide

Answer 25

• high melting and boiling point Because of huge number of strong covalent bonds

Question 26

What are the properties of graphite ?

Answer 26

• have delocalised electrons , can move which means can conduct electricity and heat
• high melting and boiling point , large number of strong covalent bonds
• hexagonal rings of carbon atoms are arranged into layers , no covalent bonds between the layers
• soft and slippery

Question 27

What is graphene ?

Answer 27

A single layer of graphite - means graphene is only one atom thick

Question 28

What are the properties of graphite ?

Answer 28

• good conductor of electricity , has delocalised electrons
• high melting and boiling point , becuase of strong covalent bonds

Question 29

Properties of fullerenes

Answer 29

• buckminsterfullerene contains 60 carbon atoms arranged in a hollow sphere. Carbon atoms form rings with either 6 carbon atoms or 5
• fullerene can be used as lubricant in machines and can be used as catalysts

Question 30

What are carbon nanotubes?

Answer 30

They are fullerenes shaped into long cylinders with a relatively small diameter
- have a very high length to diameter ratio

Question 31

What are the properties of carbon nanotubes ?

Answer 31

• high tensile strength
• delocalised electrons - good conductor of electricity and heat
• carbon nanotubes can be used to reinforce materials ( e.g. tennis rackets)

Question 32

What are polymers ?

Answer 32

They are very large molecules
They are created by joining together thousands of small identical molecules called monomers

Question 33

Properties of polymers

Answer 33

• Most polymers are solids at room temperature
• all the covalent bonds in polymers are extremely strong
• intermolecular forces in polymers are strong - takes a lot of energy to break these forces , so solid at room temp

Question 34

What does the repating unit show ?

Answer 34

• a single covalent bond
• the ‘n’ represents a large number

Question 35

Properties of metals

Answer 35

• high melting and boiling point
• good conductors of heat and electricity , because sea of delocalised electrons can move

Question 36

What is an alloy ?

Answer 36

An alloy is a mixture of metals

Alloys are harder than pure metals