P4- Atomic Structure Flashcards
What is radioactive decay
When unstable isotopes tend to decay into other elements and give out radiation as they try to become more stable
What is an alpha particle
Is two neutrons and two protons like a helium nucleus
How far does alpha particles travel in air
A few centimetres
What would stop alpha particles
A sheet of paper
What are beta particles
They are fast moving electrons released by the nucleus
What is the mass and charge of beta particles
They have no mass and charge of -1
How far can bata particles travel in air
A few metres
What can stop bata particles
A sheet of aluminium around 5 mm thick
What happens when every beta particle is emitted
A neutrons in the nucleus has turned into a proton
What are gamma rays
Waves of electromagnetic radiation released by the nucleus
how far can gamma rays travel in air
A long distance
What would stop gamma rays
By thick sheets of lead and metres of concrete
How do you write a nuclear equation
Atom before decay -> atom after decay + Radioactive element
What is half-life
Is the time taken for the number of radioactive nuclei in an isotope tohave
What are the risks of using radiation
Radiation can enter living cells, this can damage the cell or kill them completely
What is exposure to radiation called
Irradiation
What are common ways of reducing the effects of irradiation
By keeping sources in Lead-lined boxes and standing behind barriers when using them
What do you call it when unwanted radioactive atoms goes onto or into an object
Contaminated
What should you use to touch the sources
Gloves and tongs should be used to avoid particles getting stuck to your skin or under your nails
What sources are most dangerous outside the body
Beta and gamma
Why is it that beta and gamma sources are dangerous
They can penetrate the body and get to the organs
Why are alpha particles less dangerous to the body
Because it cannot penetrate the skin and is easily blocked by a small air gap
Why are alpha sources the most dangerous inside the body
Because they do all the damage in a very localised area so contamination is the major concern when working with alpha sources
