Nanoparticles

Question 1

How big are nanoparticles compared to other things?

Answer 1

Larger than atoms and molecules
Smaller than cells
(size of a few hundred atoms)

Question 2

Why are nanoparticles used in sunscreen?

Answer 2

Absorbs UV radiation to prevent cancer
Transparent as particles are very small

Question 3

What are the risks of nanoparticles?

Answer 3

• We don’t know the long term risks yet as they are new technology
• Could change/catalyse reactions in the body due to large surface area to volume ratio
• May pass through cell-surface membranes/(bloodstream)

Question 4

Why are nanoparticles used in stain-resistant clothing?

Answer 4

Large surface area to volume ratio makes them useful catalysts.
So, stain resistant clothes stay clean because the nanoparticles catalyse the break down of dirt