SC26c Nanoparticles

Question 1

bulk materials, and examples?

Answer 1

~materials that consist of huge number of atoms
~lumps and powders

Question 2

size of nanoparticles?

Answer 2

1x10-9

Question 3

nanoparticulates?

Answer 3

substances that consist of nanoparticles

Question 4

how to calculate total surface area of a cube?

Answer 4

width x height x 6

Question 5

how to calculate a cubes volume?

Answer 5

width x height x length

Question 6

how to calculate surface are to volume ratio?

Answer 6

surface area / volume

Question 7

uses of nanoparticulate materials and why? 2

Answer 7

~sunscreen - nanoparticulate titanium dioxide is transparent because its particles are very small, but it still absorbs ultraviolet radiation
~stain resistant clothing - nanoparticle materials stay clean because nanoparticles catalyse the breakdown of dirt

Question 8

risks of nanoparticles?

Answer 8

~their large surface area to volume ratios may allow them to catalyse harmful reactions or to carry toxic substances bound to their surfaces
~risks are difficult to determine because modern nanoparticulate materials have not been in use for long