UNIT 5 - RADIATION Flashcards
WHAT IS AN ISOTOPE ?
Isotopes of an element have different numbers of neutrons in their nuclei
WHAT CAUSES RADIATION ?
If the protons and neutrons are unbalanced by a large margin they become unstable. They are likely to release radioactive emissions in order to become stable (decay)
WHAT IS USED TO MEASURE RADIATION ?
Geiger Counter
WHAT IS THE UNIT FOR RADIATION ?
Becquerels (Bq)
IS RADIATION SPONTANEOUS ?
Radioactive decay is a spontaneous process.
An unstable nucleus will decay by emitting radiation but it is impossible to know when and at what rate
RECORDING DECAY
When recording the number of nuclei that decay per minute, random fluctuations causes data to vary
Improvement would be to monitor over 10 minutes and divide to find a minute. Lessens the effect of fluctuations
WHAT IS ALPHA RADIATION ?
Occurs when a nucleus decays by emitting a helium nucleus (2 protons and 2 neutrons )
WHAT IS BETA RADIATION ?
Occurs when a neutron in an unstable atom changes to a proton and emits a high energy electron.
WHAT IS GAMMA RADIATION ?
Occurs when the nucleus releases energy in the form of an electromagnetic
WHAT IS IONISING RADIATION ?
Ionising radiation can break an electron from an atom.
If this occurs in DNA molecules it can change its chemical properties, killing the cell or causing it to grow in an abnormal way (tumour)
BACKGROUND RADIATION ?
Natural low level radiation that is always present
SOURCES - Cosmic radiation, radon gas (rocks), food, rocks (granite), nuclear power, medical equipment
Medical equipment is the biggest artificial source of radiation
DISPOSING OF RADIATION ?
Nuclear power stations produce radioactive waste that must be disposed of safely
Nuclear waste is stored in drums and sealed underground with concrete. They are monitored to ensure there is no leakage
WHAT MUST BE DONE WHEN MEASURING THE RADIATION EMITTED BY AN OBJECT ?
when measuring the radioactivity of a sample the background radiation must be subtracted.
WHICH IS THE MOST IONISING FORM OF RADIATION ?
ALPHA
WHICH IS THE LEAST IONISING FORM OF RADIATION ?
GAMMA
