| A | B |
|---|
| A | mass number |
| Z | atomic number |
| isotope | same Z |
| (A-Z) | equals the number of neutrons |
| alpha particle | He nucleus (2 p and 2 n) |
| beta particle | electron ejected from the nucleus |
| gamma ray | short wavelength high energy photon |
| half-life | time for activity to halve |
| activity | no of disintegrations per second |
| daughter nucleus | nucleus after radioactive decay |
| fission | nucleus splitting in roughly equal bits |
| spontaneous fission | splitting in half without warning |
| induced fission | fission caused by neutron |
| all ionising radiations cause: | ionisation (loss/gain of electrons by atoms) |
| geiger counter | gas filled radiation detector |
| ionising radiation can be detected by: | photographic film |
| gamma rays are emitted: | following alpha or beta decay |
| E = mc^2 | energy created when mass is destroyed |
| cardboard will stop most: | alpha particles |
| 2 mm aluminum will stop most: | beta particles |
| thick lead is need to stop: | energetic gamma rays |
| low energy gamma rays are sometimes called: | x-rays |
| energetic x-rays are sometimes called: | gamma rays |
| magnetic fields affect the path of: | alphas and betas |
| magnetic fields do not affect the path of: | gammas and neutrons |
| gamma rays travel at: | the speed of light |
| alphas travel at roughly: | 5 - 10% of the speed of light |
| beta particles have a speed range of: | 30 - 99% of the speed of light |
| after beta decay, the daughter nucleus has: | increased Z by 1; A stays the same |
| after alpha decay, the daughter nucleus has: | A-4 and Z-2 |
| in nuclear equations: | total A and total Z numbers balance |
| beta particles have: | A = 0 and Z = -1 |
| a neutron has | A = 1, Z = 0 |
| a proton has: | A = 1, Z = 1 |
| critical mass | capable of sustained chain reaction |
| two common fissile nuclides are: | U-235 and Pu-239 |
| uncontrolled nuclear chain reaction | nuclear bomb |
| hydrogen bomb | fusion bomb |
| 'atomic' bomb | fission bomb |
| mass of a photon | zero |
| the material in our bodies | was originally made in stars that no longer exist |
| fission reactions normally | emit more than one neutron |
| the nucleus | takes up a tiny amount of space in the atom |
| different isotopes of an element have the same: | number of protons and electrons |
| Find x in U(328,92) -> Th(234, x) + alpha | x = 90 |
| Find y in K(40,y) ->Ca(40,20) + beta | y = 19 |
| True or false: gammas are safe? | false: gammas are not safe |
| True or false: alphas are mostly stopped by skin layers? | true: skin layers stop most alphas |
| True or false: doctors sometimes inject radioactive isotopes? | true: for example stress fracture locations |
| a 'granddaughter' nucleus | follows two decays |
| in beta decay: | a neutron changes into a proton |
| Find z: Po(211,84) has z neutrons | z = 127 |
| After three half lives; 120 gm of radioactive isotope will become: | 15 grams |
| control rods | absorb neutrons |
| fuel rods | contain fissile materials |
| coolant | takes heat away from the core |
| heat exchanger | takes heat from the coolant |
| nuclear power | generates virtually no greenhouse gases |
| wastes from nuclear power plants | are very dangerous |
| ordinary nuclear power plants | cannot become nuclear 'bombs' |
| 1 kg of uranium produces as much energy as: | 10 000 kg of coal |
