Particle size and their properties

Question 1

Particle size nano-

Answer 1

1-100 atoms, 1-100 nm, 1x10^-9 m to 1x10^-7 m

Question 2

Particle size fine

Answer 2

PM2.5, 1x10^-7 m to 2.5x10^-6 m

Question 3

Particle size coarse

Answer 3

PM10, 2.5x10^-6 m to 1x10^-5

Question 4

How to calculate surface area to volume ratio on a cube

Answer 4

find surface area (area of each face x 6), find volume (sidesideside), SA:V = 1:x or x:1

Question 5

Property of nanoparticles in sun cream

Answer 5

better skin protection from UV radiation, better coverage on skin, doesn’t leave white marks (transparent)

Question 6

Property of nanoparticles in plasters

Answer 6

silver nanoparticles have antibacterial properties

Question 7

Property of nanoparticles in self cleaning glass

Answer 7

titanium dioxide nanoparticles work with sunlight to break down dirt

Question 8

Property of nanoparticles in cosmetics

Answer 8

nanoparticles absorb deeper into the skin with no smearing

Question 9

Property of nanoparticles in nanomedicine

Answer 9

fullerenes are used as a drug delivery system as they are absorbed into the body easier

Question 10

Property of nanoparticles in catalysts for fuel cells

Answer 10

nanoparticles of platinum are used because of its high cost, large SA:V ratio

Question 11

Why is it good that nanoparticles have a high SA:V ratio

Answer 11

less material to get the same effect as a bulk material, making them ideal as catalysts

Question 12

Dangers of nanoparticles

Answer 12

long term effects on human health are unclear, w but we do know the nanoparticles can enter our body and damage our cells potentially causing cancer, studies of aquatic organisms show some evidence of harm cause by nanoparticles