Nanoparticles

Question 1

Define nanoparticle

Answer 1

A nanoparticle is a structure that is 1-100 nm in size. It contains a few hundred atoms

Question 2

Convert the following Nanometers into metres

3nm
85nm
45nm
32nm

Answer 2

0. 000000003
1. 000000085
2. 000000045
3. 000000032

Question 3

Nanoparticles have very different properties and uses from the bulk material. This is due to ….

Answer 3

Their high surface area to volume ratio

Question 4

Bulk gold metal is very unreactive, however gold nanoparticles can be used as a …. in some chemical reactions

Answer 4

Catalyst

Question 5

How to calculate the surface area of a cube?

e.g a cube 10cm in length

Answer 5

10x 10
= 100cm2

100 x 6
= 600cm2

Question 6

How to calculate the volume of a cube

e.g 50cm in length

Answer 6

l x b x h
50 x 50 x 50
= 125000cm3

Question 7

How to calculate surface area to volume ratio

e.g 50cm in length

Answer 7

Surface area 1: 15000cm2
Volume 1: 125000cm

Surface area to volume ratio 1:
15000 : 125000
15 : 125
0.12 : 1

Question 8

What happens to the surface area to volume ratio when the sides of the cube have decreased by a factor of 10?

Answer 8

When the sides of a cube have decreased by a factor of 10, the surface area to volume ratio increases by a factor of 10

Question 9

Name 4 benefits of using nanoparticles of Zinc Oxide in sun cream

Answer 9

1. Provides more effective protection from the sun’s ultraviolet rays
2. They are colourless which makes sun cream invisible on the skin and therefore easier to rub in
3. They give better skin coverage to the sun cream
4. They do not degrade on exposure to the sun

Question 10

Name two risks of using nanoparticles of zinc oxide in sun cream

Answer 10

1. Harmful effects on the environment
2. There is potential cell damage in the body. Nanoparticles are small and may be able to be breathed in or penetrate cell membranes