SC26 Bulk and Surface Properties of Matter including Nanoparticles

Question 1

What are the two types of ceramics?

Answer 1

Glass and Clay

Question 2

How are glass ceramics made?

Answer 2

1. By melting sand with other substances, especially metal oxides
2. Then allowing the molten liquid to cool and solidify

Question 3

How are clay ceramics made?

Answer 3

1. Heating clay to high temperatures, causing crystals to form and join together.
2. Often coated in a glaze, which hardens to form a hard, smooth, opaque and water proof layer

Question 4

What are the properties of glass ceramics?

Answer 4

• transparent
• hard
• brittle
• durable

Question 5

What are the properties of clay ceramics?

Answer 5

• opaque
• strong
• hard
• brittle

Question 6

Name the two materials that don’t conduct heat or electricity?

Answer 6

Glass and clay ceramics

Question 7

What material is a good conductor of heat and electricity?

Answer 7

Metal

Question 8

State some properties of metals

Answer 8

• malleable
• ductile
• shiny

Question 9

What are polymers?

Answer 9

Substances with high average relative formula masses

Question 10

What are the properties of polymers?

Answer 10

• can be tailored to have specific properties
• but they are not conductors of heat and electricity

Question 11

What is a composite material?

Answer 11

A material that consists of two or more materials with different properties

Question 12

What is an alloy?

Answer 12

Metals that are mixed with other elements, that have different properties to the original two elements

Question 13

What are two components of composite materials?

Answer 13

1. Reinforcement
2. Matrix

Question 14

What is the role of the reinforcement?

Answer 14

Fibres/other material which make up the bulk of the composite materials

Question 15

What is the role of the matrix?

Answer 15

Binds the reinforcement together

Question 16

Name some examples of composite materials

Answer 16

• Fibreglass
• steel reinforced concrete

Question 17

Name the reinforcement and the matrix in fibreglass

Answer 17

Reinforcement: glass fibres
Matrix: polymer resin

Question 18

What are the properties of fibreglass?

Answer 18

• strong in tension
• flexible
• strong
• stiff
• lightweight

Question 19

What are the reinforcement and matrix in concrete?

Answer 19

Reinforcement: steel
Matrix: concrete

Question 20

What are the properties of steel reinforced concrete?

Answer 20

Strong in tension and compression, which allows reinforced concrete to be strong and slightly flexible

Question 21

Why is glass used in construction?

Answer 21

• highly durable
• high compressive strength
• transparent

Question 22

What are the uses of metal?

Answer 22

Used in electrical cabling and electronics due to their ability to conduct electricity

Question 23

What is polymer used in?

Answer 23

Insulating electrical materials

Question 24

What are clay ceramics used for?

Answer 24

Making brick, China and porcelain

Question 25

Define **nanoparticles**

Answer 25

Structures only 1-100 nanometers in size, and usually contain around 100 atoms

Question 26

What do the properties of nanoparticles depend on?

Answer 26

Their large surface area to volume ratios

Question 27

What happens to the surface area to volume ratio as particles decrease in size?

Answer 27

It increases

Question 28

What are the uses of nanoparticles?

Answer 28

- sunscreen: titanium dioxide blocks UV light - Pigment in white paint in bulk

Question 29

Why can nanoparticles act as catalysts?

Answer 29

Due to their large surface area to volume ratio

Question 30

What are some possible risks of nanoparticles?

Answer 30

- once inside the body, they may catalyse harmful reactions - easy to breath in - toxic substances could bind to them