Nanoparticles

Question 1

What is a nanoparticle?

Answer 1

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

Question 2

How large is a nanometre?

Answer 2

1 nm = 0.000000001m (1x(10x-9)m)

Question 3

Why do nanoparticles have different properties to bulk materials?

Answer 3

Their high surface area to volume ratio.

Eg, bulk gold is very unreactive, however gold nanoparticles can be used as a catalyst in some reactions.

Question 4

How does one calculate surface area?

Answer 4

Step 1: calculate area of 1 side

Step 2: multiply by number of sides

Question 5

How do you calculate volume?

Answer 5

LxBxH

Question 6

How do you find a surface area to volume ratio?

Answer 6

Divide both sides until volume side reaches 1
Eg.

15000: 125000
15: 125
0. 12:1

Question 7

List some benefits of using zinc oxide nanoparticles in sun creams

Answer 7

They give better skin coverage to the Sun cream

They provide more effective protection from the suns ultraviolet rays.

They are clear and colourless which makes them invisible on the skin and easier to rub in

They do not degrade on exposure to the Sun

Question 8

List some risks to using nanoparticles in sun creams?

Answer 8

Nanoparticles are so small they may be able to be inhaled or penetrate cell membranes, causing cell damage. Zinc nanoparticles may be more reactive or toxic in the body than the bulk material.

May cause environmental damage.