| What must electrons absorb to move around/leave the atom? | EM radiation (Electromagnetic) |
| What do electrons do once [_] is absorbed? | They move to a higher energy level further from the nucleus |
| What happens if electrons release [_] instead of absorbing it? | They move to a lower energy level closer to the nucleus |
| What ion is created if electrons leave the atom? | A positively charged ion |
| What are alpha particles? | Helium nuclei |
| Symbol for an alpha particle? | Symbol: |
| How far can alpha particles travel in air? | A few cm |
| What are alpha particles absorbed by? | A piece of paper |
| Ionisation in alpha particles? | Strongly ionising |
| Example of where alpha particles are used | In smoke alarms |
| What are beta particles? | High- Speed Electrons released from the nucleus |
| Symbol for a beta particle? | Symbol: |
| How far can beta particles travel in air? | A few metres |
| Ionisation in beta particles? | Moderately ionising |
| What are beta particles absorbed by? | A sheet of aluminium |
| What happens for every beta particle emmitted? | A neutron in the the nucleus has turned into a proton |
| Example of where beta particles are used | Beta emitters that test the thickness of sheets of metal |
| What are gamma rays? | Waves of electromagnetic radiation released by the nucleus |
| Symbol for a gamma ray? | Symbol: |
| How far can gamma particles travel in air? | Long distances |
| What are gamma particles absorbed by? | Thick sheets of lead or concrete |
| Ionisation in gamma particles | Weakly ionising- don't usually collide with atoms |
| What has to balance? | Atomic numbers and masses |
| Atomic decay equation? | Atom before decay = atom after decay + radiation emitted |
| What happens to the atomic number and mass of an atom that endures alpha decay/ emits an alpha particle? | Atomic number reduces by 2, mass reduces by 4 |
| What happens to the atomic number and mass of an atom that endures beta decay/ emits a beta particle? | Atomic number increases by 1 (neutron has been turned into a proton), mass doesn't change (electron lost but proton gained) |
| What happens to the atomic number and mass of an atom that endures gamma decay/ emits a gamma particle? | There is no change. Energy is released from the atom. |
| What is radiation measured by? | Geiger-Muller tube and counter |
| What does the [_] record? | Number of radiation counts reaching it per second |
| What is half-life? | The amount of time it taken for the number of radioactive nuclei in an isotope to halve |
| What is Activity? | The rate of radioactive decay |
| What is the unit for Activity? | Bq |
| What does a short half-life mean? | The Activity will fall quickly because the nuclei in the isotope are very unstable and decay rapidly |
| What is irradiation? | Exposure to radiation |
| What is contamination? | Radioactive atoms getting onto or into an object |
| Which types of radiation are the most dangerous outside the body? Why? | Beta and gamma- can penetrate skin |
| Which type of radiation is the most dangerous inside the body? Why? | Alpha- damages in localised areas |
| Why are high doses of radiation dangerous? | Can ionise atoms and molecules in living cells, killing them leading to radiation sickness |
