Alpha particles, beta particles and gamma rays are types of nuclear radiation.
i- What does an alpha particle consist of?
[1 mark]
SOLUTION
An alpha particles contains 2 protons & 2 neutrons.
ii- A krypton (Kr) nucleus decays into a rubidium (Rb) nucleus by emitting a beta particle.
Complete the nuclear equation for this decay by writing the missing number in each box.
[2 marks]
SOLUTION
Always remember that the sum of atomic number and atomic mass on both sides of the equation is always same.
iii- Internal contamination of the human body means radioactive material is inside the human body.
Explain how the risk from internal contamination is different to the risk from external irradiation by a source of alpha radiation.
[5 marks]
SOLUTION
Alpha particles cause the most damage if they get inside the body, as they are strongly ionising; this harms tissues and organs and may also cause mutation of cell. Whereas, an alpha source’ external contamination is less dangerous as the radiation only travels short distances, so does not enter our body as it has low penetrating power.
