Term
What do all radioactive substances contain? |
|
Definition
|
|
Term
|
Definition
When an unstable nucleus breaks down spontaneously to create radiation. It is random. |
|
|
Term
What is background radiation? |
|
Definition
Background radiation is naturally occurring in the environment that come from rocks or outer space. It is around us all the time. |
|
|
Term
How do we detect the presence of radioactivity? |
|
Definition
A Geiger Counter. The highly positively charged particles pass through a gas which creates a charge by ionising it. It needs electrons so it rips them off the gas. The current produced can produce a noise or activate a counter to measure this presence. |
|
|
Term
What is the range of each type of radiation? |
|
Definition
Alpha: 2-5cm of air Beta: 1m of air Gamma: Several meters of concrete |
|
|
Term
What is the mass of each type of radiation? |
|
Definition
Alpha: 2 Beta: 1/2000 Gamma: No mass |
|
|
Term
What is the charge of each type of radiation? |
|
Definition
Alpha: +2 Beta: -1 Gamma: No charge |
|
|
Term
What is the ionisation of each type of radiation? |
|
Definition
Alpha: Strong Beta: Weak Gamma: Very weak |
|
|
Term
What is the effect in electric and magnetic fields for each type of radiation? |
|
Definition
Alpha: Deflected to negative Beta: Deflected to positive Gamma: Will go straight through |
|
|
Term
|
Definition
| The time it takes for half the number of nuclei in a radioactive isotope in a sample to halve. Rate of decay is proportional to the number present. |
|
|
Term
How do we determine the use we can make of a radioactive substances? |
|
Definition
It's half life and the type of radiation it gives out. |
|
|
Term
How can we use radiation to date? |
|
Definition
Carbon Dating: We measure the amount of radioactive carbon in wood (the count rate) and compare it the count rate of the same mass of living wood. Uranium Dating: We look at the ratio of Uranium to lead because the uranium decays into lead. |
|
|
