13.5 13.4 Flashcards
where do ultra violet rays lie un the electromagnetic spectrum
between violet light and x rays
what can ultra violet waves be used for and how does this work
security marker pens - the chemicals absorb ultra violet waves and then emit visible light
is ultraviolet harmful to human eyes - explain
yes they can cause blindness
uv light wavelengths are smaller then visible light so carry more energy
what else on the body are UV rays harmful to
skin
what type of material stops x-rays and gamma rays travelling through them
a dense one
e.g lead
why do x-rays and gamma rays have similar properties
have short wavelengths, carry much more energy per second than longer wavelengths,
why do x-rays and gamma rays differ
x-rays are produced when electrons or other particles moving at high speeds are stopped - x-ray tubes are used to produce x-rays
gamma rays are produced by radioactive substances when un stable nuclei release energy, gamma rays are more penetrating due to the shorter wavelength
what are x-rays used for
to create images of broken limbs and to detect internal cracks in metal objects
what are gamma rays used for
killing harmful bacteria
exposing surgical instuments in sealed plastic wrappers to gamma rays kills bacteria on the instruments
killing cancerous tumours
what is ionsing radiation
when x-rays and gamma rays pass through substances they can knock the electrons out of atoms
what does a high dose of ionising radiation do
kills cells
what does a low dose of ionising radiation do
cause gene mutation and cancerous growth
what does a film badge do
tells a person when they have been open to too much radiation and must stop working
