Nanoparticles

Question 1

What is a nanoparticle

Answer 1

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

Question 2

How many metres is a nanometre

Answer 2

0.000000001

Question 3

Why do nanoparticles have very different properties and uses from bulk material

Answer 3

Due to a large surface area : volume ratio

Question 4

How to calculate surface area : volume ratio

Answer 4

1) calculate surface area - calculate surface area of one side then use that to calculate surface area of all sides
2) calculate volume - l x b x h
3) calculate surface area to volume ratio - simplify to its simplest form ( volume must always be 1)

Question 5

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

Answer 5

When sides have DECREASED by a factor of 10, the surface area to volume ratio INCREASES by a factor of 10

Question 6

Why do nanoparticles have a very large surface area to volume ratio

Answer 6

Due to their very small size which leads to them showing different properties from their bulk material

Question 7

Benefits of using nanoparticles of zinc oxide in sun cream

Answer 7

1) gives better skin coverage to the suncream.
2) provides more effective protection from the sun’s UV rays.
3) they’re colourless which makes sunscreen invisible and easier to rub in.
4) doesn’t degrade on exposure to the sun.

Question 8

Risks of using nanoparticles of zinc oxide in suncream

Answer 8

1) potential cell damage to body.
2) nanoparticles are so small they can be breathed in or penetrate cell membranes. In the body, the nanoparticles may be more reactive or more toxic than in bulk material.
3) may have harmful effects on the environment.
4) cost - more expensive

Question 9

Everyday uses of nanotechnology

Answer 9

Anti microbial uses, sunscreens, clothes, sports equipment, quantum dots