Radiation and Risk Flashcards
What is an isotope?
Atoms of an element with the same number of protons but different number of neutrons.
Isotopes of an element have the same atomic number but a different mass number.
What do unstable isotopes do?
What is the process called?
Give out radiation from their nuclei to try and become more stable.
Called Radioactive decay.
What is the radiation called that are emitted from radioactive decay in unstable isotopes?
Nuclear radiation.
What are isotopes that give out nuclear radiation called?
radioactive isotopes.
The four types of nuclear radiation -
Alpha particle / two neutrons and two protons.
Beta particle / fast moving electron.
Gamma rays / waves of electromagnetic radiation.
Neutrons.
What is ionizing radiation?
Radiation that can knock electrons off atoms and turn them into ions.
The ionizing power of radiation is how easily it can do this.
Alpha beta and gamma rays are all types of ionizing radiation.
Alpha particles.
Ionising power - Strong or weak?
Range in air - few cm, few m, or long distance?
Stopped by what- paper, aluminum or thick sheets of lead or metres of concrete?
Strong.
Few centimeters.
A sheet of paper.
Beta particles.
Ionising power - Strong, moderate or weak?
Range in air - few cm, few m, or long distance?
Stopped by what- paper, aluminum or thick sheets of lead or metres of concrete?
Moderate
Few metres
A sheet of aluminum
Gamma rays.
Ionising power - Strong or weak?
Range in air - few cm, few m, or long distance?
Stopped by what- paper, aluminum or thick sheets of lead or metres of concrete?
Weak
Long distance
Thick sheet of lead or concrete.
What do nuclear equations to show radioactive decay look like?
Nucleus before decay -> Nucleus after decay + radiation emitted.
(Rule; total mass and atomic numbers must be equal on both sides of the arrow)
Does aloha decay decrease or increase the charge and mass of a nucleus?
decreases
this is because it’s made of two protons and two neutrons, therefore when it is emitted, the atomic number goes down by two and the mass number goes down by four.
Does beta decay increase or decrease the charge of the nucleus?
Increase.
During beta decay, a neutron in the nucleus turns into a proton.
This means the nucleus has one more proton so the atomic number goes up by 1.
Also means the positive charge of the nucleus increases.
Do gamma rays change or not change the charge or mass of a nucleus?
Not change.
What is how quickly unstable isotopes decay measured using?
Activity and half life.
What is the number of decays per second called?
Activity of a source is the rate at which it decays. - How many unstable nuclei decay every second.
Measured in becquerels aqa bq.
The half life is the time taken for what?
Number of nuclei of a radioactive isotope in a sample to halve.
How does ionising radiation damage cells?
Can enter living cells and ionize atoms in them, which can damage cells by causing cancer or kill cells completely.
What does irradaiation mean : how can it be caused?
Radiation from a radioactive source able to reach something.
What does radioactive atoms getting into an object (contaminating it) do?
(clue; atoms)
Contaminating atoms might decay and release radiation which could harm youz
What two types of radiation are the most dangerous to be irradiated by?
Beta and gamma sources, as they have long ranged so more radiation will reach you than alpha.
Inside the body, what radiation source is the most dangerous to be contaminated by?
Alpha particles, as it is the most ionising type of radiation.
Outside the body, it is the least dangerous as it can’t get through skin.
