P13.4 Ultraviolet waves, X-rays, and gamma rays Flashcards
What is the problem of UV rays?
Can cause sunburn
Prematurely age your skin
What are the differences between x-rays and gamma rays?
X-rays are produced when electrons or other particles moving at high speeds are stopped
Gamma rays are produced by radioactive substances when unstable nuclei release energy
Gamma rays have shorter wavelengths than X-rays - so they can penetrate substances more than X-rays can
How can X-rays be used to detect internal cracks?
Because the more dens a substance is - the more X-rays it absorbs from and X-ray beam passing through it
Why is gamma rays used in killing harmful bacteria?
Because they can stop infection spreading in hospitals
Bacteria can cause food poising
How can gamma rays be used to kill cancer cells?
A narrow beam of gamma rays from a radioactive source (cobalt -60) is directed at the tumour
The beam is aimed at it from different directions to kill the tumour but not the surrounding tissue
What is ionisation?
When rays passing through a substance can knock electrons out of atoms in the substance
The atoms become charged because they lose an electron
What is the problems of ionisation?
High does can kill living cells
Low does can cause gene mutation and cancerous growth
What is a film badge?
The badge shows that it is over - exposed to ionising radiation - its wearer is not allowed to continue working with the equipment for a period of time
