6187434
Description
Flashcards by Mel Hughes, updated more than 1 year ago
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Created by Mel Hughes
about 8 years ago
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| Question | Answer |
| Which part of an atom might emit alpha particles? | The nucleus |
| What happens to the rate of radioactive decay if the temperature is doubled? | It stays the same |
| Why did most alpha particles pass straight through the foil in Rutherford's experiment? | Most of the atom is empty space |
| What did the alpha particle scattering experiment suggest about the structure of the nucleus? | The nucleus is where most of the mass of the atom is concentrated, very small and positively charged |
| What is the relative charge of an alpha particle? | +2 |
| What is the relative charge of a beta particle? | -1 |
| Which type of nuclear radiation is the least penetrating? | Alpha |
| Which type of nuclear radiation is the least ionising? | Gamma |
| What happens to the count rate of a radioactive sample over time? | It decreases |
| What has happened to the original count rate of a radioactive sample after two half-lives have passed? | It has decreased to one quarter of its original value |
| Why isn't an alpha source used as a tracer in medicine? | Alpha particles are very poorly penetrating, so they would not be detected outside/ Alpha is very ionising so would be damaging to the patient |
| Why do medical tracers have half-lives of just a few hours? | To allow time to complete the procedure but minimise unnecessary exposure of the patient |
| What is the effect of pressure on the rate of radioactive decay? | It has no effect |
| What is background radiation? | Radiation that is around us all the time |
| What was Rutherford's alpha particle scattering experiment? | Firing alpha particles at a thin metal foil |
| What happens to the mass number of a nucleus when it emits a beta particle? | It stays the same |
| What happens to the atomic number of a nucleus when it emits a beta particle? | It goes up by 1 |
| What happens to the mass number of a nucleus when it emits an alpha particle? | It goes down by 4 |
| What happens to the atomic number of a nucleus when it emits an alpha particle? | It goes down by 2 |
| Why is gamma radiation not deflected by electric and magnetic fields? | Gamma radiation is uncharged |
| What has happened to the number of atoms undergoing nuclear decay in a sample after three half-lives have passed? | It has decreased to one-eighth of its original value |
| Why is alpha radiation unsuitable for monitoring the thickness of metal foil? | Alpha radiation would not be able to ass through the foil, irrespective of thickness |
| A radioactive isotope has a half-life of seven hours. A sample of the isotope has a mass of 4 milligrams. What mass of the isotope has decayed after 14 hours? | 3 milligrams |
| A sample of a radioactive isotope contains 100000 atoms of the isotope. How many atoms of the isotope will remain after three half-lives? | 12500 |
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