Random Flashcards
(17 cards)
What happens during alpha decay?
The unstable nucleus emits an alpha particle, which is 2 protons and 2 neutrons
How do the mass number and atomic number of an unstable nucleus change during alpha decay?
The mass number decreases by 4 and the atomic number decreases by 2.
What happens during beta decay?
A neutron decays into a proton and an electron. The electron is emitted from the nucleus as a beta particle.
How do the mass number and atomic number of an unstable nucleus change during beta decay?
The mass number stays the same and the atomic number increases by 1.
What happens during gamma decay?
High energy electromagnetic radiation (gamma ray) is emitted from the nucleus. This often happens alongside alpha or beta decay.
Do the mass number or atomic number of an unstable nucleus change during gamma decay?
No, the mass and atomic numbers stay the same during gamma decay
Can you tell when an individual nucleus will decay?
No, the process is random so there is no way to predict it.
What is the ‘activity’ of a radioactive sample?
Activity is the overall rate of decay of all of the radioactive isotopes in a sample
What are the two definitions for the ‘half-life’ of a radioactive sample?
The time taken for the activity to halve. The time taken for the number of radioactive nuclei in a sample to halve.
What device is used to record radioactive decays?
Geiger-Muller tube and counter.
What is the ‘count rate’ of a radioactive sample?
The number of decays measured each second by a Geiger-Muller tube.
What is ionising radiation?
Ionising radiation is radiation that has enough energy to remove an electron from an atom/molecule, causing it to become positively charged.
Name 4 types of ionising radiation.
Alpha radiation, Beta radiation, Gamma radiation, X-rays
When exposed to radiation, what factors determine how harmful the radiation is?
The type of radiation.
Where you’re exposed to the radiation.
The amount of radiation you receive.
For radioactive substances inside the body, which type of radiation is the most harmful? Explain.
Alpha radiation, because it’s the most ionising, so damages our cells the most.
Why is ionising radiation harmful?
It can damage our cells, or cause mutations which can lead to cancer.
When exposed to a radioactive substance, which factors affect the amount of radiation you receive?
How far away from the source you are
How long you’re exposed for
How radioactive the substance is
