Ultraviolet

Question 1

What is the wavelength of ultraviolet waves?

Answer 1

10^-8 m

Question 2

Why can ultraviolet waves be harmful?

Answer 2

ultraviolet radiation can damage cells and ionise (remove electrons from) the atoms in our DNA.

Question 3

What are the side effects of UV waves/radiation?

Answer 3

This can cause sunburn, DNA mutations and cancer.

Question 4

What are fluorescence?

Answer 4

this is a property of certain chemicals, when exposed to ultraviolet waves, they absorb them and emit visible light.

Question 5

What do fluorescent lights do?

Answer 5

they generate UV radiation which is absorbed then re-emitted as visible light by a layer of a compound called phosphor on the inside of the bulb. They’re efficient and therefore good to use for long periods of time.

Question 6

What are security pens?

Answer 6

these are used to mark objects with writing that is only visible under ultraviolet light. Can help identify stolen property.

Question 7

How are UV waves used in tanning?

Answer 7

the sun emits ultraviolet radiation and this can give you a sun tan if you spend a lot of time outside. Tanning salons also use UV lamps to give you a sun tan when it is not sunny outside.

Question 8

What is the problem with too much exposure to UV radiation?

Answer 8

However, lots of exposure to ultraviolet radiation can be harmful.