Nanoparticles

Question 1

Define nanoscience

Answer 1

Nanoscience is the study of very tiny particles or structures between 1 and 100 nanometres in size - where 1 nanometre = 10 -9 metres

Question 2

Write 1mm in metres

Answer 2

1mm= 1 x 10 -3 m
A thousandth of a metre

Question 3

Write 1 micrometre in metres

Answer 3

1 μm = 1 x 10 -6 m
A millionth of a metre

Question 4

Write 1 nanometre in metres

Answer 4

1nm = 1 x 10 -9 m
A billionth of a metre

Question 5

State another name for coarse particles

Answer 5

Coarse particles can be referred to as:

PM10 (subscript 10)

Dust

Question 6

State the diameter of Coarse particles

Answer 6

Coarse particles (PM10) have diameters between 1 x 10 -5 m and 2.5 x 10 -6 m.

Question 7

How many atoms do Coarse particles contain

Answer 7

Coarse particles contain tens of thousands of atoms

Question 8

State another name for Fine particles

Answer 8

Fine particles can be referred to as:

PM2.5 (subscript 2.5)

Question 9

State the diameter of Fine particles

Answer 9

Fine particles (PM2.5), have a diameter between 100
and 2500 nm
(1 x 10-7 m and 2.5 x 10-6 m).

Question 10

How many atoms do Fine particles contain

Answer 10

Fine particle contain several thousand atoms

Question 11

State the diameter of nanoparticles

Answer 11

Nanoparticles have a diameter between 1 and 100 nanometres

Question 12

How many atoms do Nanoparticles contain

Answer 12

Nanoparticles contain a few hundred atoms

Question 13

What is the relationship between the particle size and surface area to volume ration

Answer 13

As the side of cube decreases by a factor of 10 the surface area to
volume increases by a factor of 10.

Question 14

Show the relationship between particle size and surface area to volume ration, with cubes.

Answer 14

file:///C:/Users/44748/Documents/nanoparticles.pdf

The size of the side of a cube is 10 cm

Surface area = 10 x 10 x 6 = 600 cm2

Volume = 10 x 10 x 10 = 1000 cm3

Surface Area : Volume ratio = 600/1000 = 0.6 /cm

The size of the size of a cube is 1 cm

Surface area = 1 x 1 x 6 = 6

Volume = 1 x 1 x 1 = 1

Surface Area : Volume ratio = 6/1= 6 /cm

Question 15

How big is the surface area : volume ratio of nanoparticles

Answer 15

Nanoparticles have a huge surface area : volume ratio

Question 16

What does this statement mean

Nanoparticles have a huge surface area : volume ratio

Answer 16

Nanoparticles have a huge surface area : volume ratio

This statement means that even a small amount of nanoparticles has a massive surface area.

Question 17

State the uses of nanoparticles

Answer 17

Uses of nanoparticles

Medicines
Sun creams
Cosmetics
Deodorants
Electronics
Catalysts
Construction materials

Question 18

State some of the risks of nanoparticles

Answer 18

It is possible that nanoparticles can be absorbed into the body and enter our cells.
ESPECIALLY WHEN NANOPARTICLES ARE USED IN APPLICATIONS SUCH AS
COSMETICS
DEODORANTS
SUN CREAMS

No-one knows the potential long-term effects of this.

It is important that nanoparticles are studied and used carefully

Question 19

How big is a nanometre

Answer 19

A nanometre is 1 x 10 -9 metres

Question 20

How many atoms are nanostructures made up of

Answer 20

Nanostructures are made up of a few hundred atoms

Question 21

How big is a micrometre in metres

Answer 21

A micrometre is 1 x 10 -6 metres

Question 22

Why do nanoparticles have different properties to the same material when in bulk

Answer 22

Nanoparticles have a huge proportion of their atoms or molecules on the surface. They have a large surface area : volume ration which changes the properties to their bulk materials

Question 23

If the side of a cub decreases by a factor of 10, what is the relationship with is surface area to volume ratio

Answer 23

If the side of a cube decreases by a factor of 10, the surface area to volume ration of the cube will increase by 10

Question 24

Why are nanoparticles so reactive and how does this affect how much is needed compared to bulk materials

Answer 24

Large percentages of a nanoparticles atoms are at the surface and are available to react. This means small amounts are required in chemical reactions compared to bulk materials

Question 25

What does a high surface area to volume ratio cause in nanoparticles

Answer 25

A high surface area to volume ration changes their properties compared to large molecules