Topic 6 Flashcards
What are alpha, beta minus, positron, gamma rays and neutron radiation emitted from
Unstable nuclei in a random process
What are alpha , beta minus, positron and gamma rays
Ionising radiation
Describe detecting radioactivity with Geiger counter (geiger - muller tube)
Ionising radiation enters a tube full of low pressure gases.
It ionises the atoms in the gas, knocking electrons out of the atoms.
The gas can now conduct electricity and completes an electric circuit. Current flows between electrodes.
The current produces a clicking noise.
The count-rate is the number of decays recorded each second.
Describe detecting radioactivity with photographic film
Ionising radiation has the same effect on photographic film as light.
A bright spot appears wherever the ionising radiation hits the film.
What is an alpha particle
Equivalent to a helium nucleus
What is a beta particle
An electron emitted from the nucleus
What is a gamma ray
Electromagnetic radiation
Compare beta radiation, gamma and alpha in terms of their ability to ionise and penetrate
Beta radiation is more ionising than gamma but less than alpha
Can pass through paper but is stopped by aluminium foil ( beta)
When penetrating it is stopped only by centimetres of lead or concrete (gamma)
does a lot of damage when penetrating but is stopped by a small amount of matter like paper (alpha ). Does a lot of damage but doesn’t get through very far
Which is the most penetrating type of radiation?
Gamma
Describe the process of b- decay
B- decay takes place in the nucleus when a neurone decays into a proton
Describe the process of B+ decay
When a proton is converted to a neutron and the process creates a positron
Explain the effects on the atomic number and mass number of radioactive decays
Changes the number of protons in the nucleus of that atom which then changes the element
What does nuclei that have undergone radioactive decay often undergo
Nuclear rearrangement with a loss of energy as gamma radiation
