C2

Question 1

Definition of melting point?

Answer 1

The temperature a which a solid turns into a liquid

Question 2

What is density?

Answer 2

Mass of a given volume of the material

Question 3

When should outliers be discarded?

Answer 3

Only if there was an error in the measurement.

Question 4

How do you get the true value?

Answer 4

By calculating the mean

Question 5

Name 3 properties of metals

Answer 5

Shiny, malleable, and electrical conductors

Question 6

Can all metals conduct electricity?

Answer 6

YES!!!

Question 7

What are Natural materials?

Answer 7

Materials from living things which require little processing.

Question 8

Give 2 examples of natural materials?

Answer 8

Silk and wool

Question 9

What are Synthetic materials?

Answer 9

Materials that are manufactured by chemical reactions using raw materials.

Question 10

Why have synthetic materials replace natural materials?

Answer 10

1. Some natural materials are in short supply
2. They can be designed to give particular properties
3. They are cheaper and can be made in quantity needed

Question 11

What are hydrocarbons made of?

Answer 11

Hydrogen and Carbon atoms

Question 12

What is crude oil made up of ?

Answer 12

A Mixture of hydrocarbons

Question 13

How do you seperate crude oil?

Answer 13

Using fractional distillation

Question 14

How does FD seperate crude oil?

Answer 14

It seperates them using boiling points

Question 15

As the hydrocarbon chain length increases…

Answer 15

The forces between these molecules increase.

Question 16

Why do larger molecules have higher boiling points

Answer 16

Because they need more energy to break intermolecular forces

Question 17

The smaller the molecule chain…

Answer 17

the lower the boiling point.

Question 18

What is a polymer?

Answer 18

A chain of monomers

Question 19

What is the process that makes a polymer?

Answer 19

Polymerisation

Question 20

When are the forces strongest?

Answer 20

The closer they are, the stronger they are.

Question 21

The stronger the force…

Answer 21

The more energy is needed to seperate the molecules and the higher the melting point.

Question 22

What does LDPE stand for?

Answer 22

Low density polyethene

Question 23

What are the properties of LDPE ?

Answer 23

LDPEs have BRANCHES which make the intermolecular forces weak

Question 24

What are the properties of HDPE?

Answer 24

HDPEs Dont have branches which makes the intermolecular forces strong

Question 25

Give an example of LDPE and HDPE?

Answer 25

Carrier bags and Water pipes

Question 26

What do plasticisers do?

Answer 26

Plasticisers make polymers softer by keeping the chains apart and weakening the forces between them

Question 27

What can soften when heated and be moulded into shape.

Answer 27

Thermoplastics

Question 28

What contains cross-links and cannot soften when heated

Answer 28

Thermosetting

Question 29

How can Crytallinity be increased?

Answer 29

By removing branches, making the chain as flat as possible

Question 30

What are Nanoparticles?

Answer 30

Material containing up to a thousand atoms

Question 31

Name 3 ways in which nanoparticles occur?

Answer 31

1. Naturally ie seasalt spray 2. by accident, in solid particulate when fuels burn 3. can be designed in laboratories

Question 32

What are structures made up of nanoparticles measured in?

Answer 32

Nanometres (nm)

Question 33

Why are nanoparticles effective catalysts?

Answer 33

Because they have a large surface area. Increasing the surface area provides more sites for reactions to take place.

Question 34

What type of nanoparticle kills bacteria?

Answer 34

Silver nanoparticles

Question 35

What are Titanium oxide nanoparticles used in?

Answer 35

Sunscreen as the make it transparent and absorb UV light

Question 36

What do you get when you mix Nanoparticles with metals or ceramics?

Answer 36

Composites

Question 37

Why would add nanoparticles to plastic sports equipment or tennis balls?

Answer 37

Adding them to sports equipment makes it stronger and makes tennis balls bounce longer

Question 38

What is Nanotechnology?

Answer 38

The science of making and using nanoparticles

Question 39

Why are Silver nanoparticles dangerous?

Answer 39

They can be washed out of clothing, get into the sewage system and kill good bacteria.

Question 40

TRUE OR FALSE: Nanoparticles cant pass through the skin into blood?

Answer 40

FALSE, They can and the effects are unknown.

Question 41

Why are people afraid of nanoparticles in the air?

Answer 41

Because if breathed in , they could cause lung or brain damage.

Question 42

Why are some not afraid of nanoparticles?

Answer 42

Because they occur naturally like in soot and volcanic dust

Question 43

In general why are people scared?

Answer 43

Because we don't know enough about nanoparticles.