The cards Question What is background radiation? Tap to flip Answer The radiation in the surroundings of a particular place. Question What causes background radiation? Tap to flip Answer Unstable nuclei that are around us all of the time. Question Roughly what is the radius of an atom? Tap to flip Answer About 1 × 10⁻¹⁰ m. Question About how many times smaller is the radius of an atomic nucleus than that of the atom? Tap to flip Answer About 10 000 times smaller. Question Which part of an atom contains most of its mass and all of its positive charge? Tap to flip Answer The nucleus. Question Which experiment, carried out by Rutherford in 1909, gave evidence for the size and nature of atomic nuclei? Tap to flip Answer The alpha particle scattering experiment. Question Can atoms be seen with a powerful optical microscope? Tap to flip Answer No: atoms are far too small to see; our descriptions of them are models based on evidence. Question What is a nucleon? Tap to flip Answer A particle in a nucleus: a proton or a neutron. Question What does the atomic (proton) number of a nucleus give? Tap to flip Answer The number of protons in the nucleus. Question What does the mass (nucleon) number of a nucleus give? Tap to flip Answer The total number of nucleons in it (protons + neutrons). Question Besides protons, the atomic number of an element also equals the number of which particle in each atom? Tap to flip Answer Electrons. Question What are isotopes? Tap to flip Answer Atoms of the same element with different numbers of neutrons. Question What are the electric charge and mass number of a proton? Tap to flip Answer Charge +1, mass number 1. Question What are the electric charge and mass number of a neutron? Tap to flip Answer No charge, mass number 1. Question Which force is introduced to explain why nuclei do not self-destruct despite electrostatic forces between protons? Tap to flip Answer The strong nuclear force. Question What is alpha decay? Tap to flip Answer The emission from a nucleus of a particle made of two protons and two neutrons. Question What are the mass and charge of an alpha particle? Tap to flip Answer Mass 4, charge +2. Question What happens in beta-minus decay? Tap to flip Answer A neutron changes into a proton and a high-speed electron is emitted from the nucleus. Question What are the mass and charge of a beta particle? Tap to flip Answer Mass close to zero, charge –1. Question What is gamma radiation? Tap to flip Answer Electromagnetic radiation emitted from a nucleus that reduces the nucleus's energy. Question What does a nucleus usually emit after an alpha or beta decay? Tap to flip Answer Some gamma radiation. Question What does a nuclear equation show? Tap to flip Answer The particles in a nuclear decay, with the electric charge and mass number of each. Question What is ionisation? Tap to flip Answer The removal of one or more outer electrons from an atom. Question What is an atom left with a positive charge by ionising radiation called? Tap to flip Answer An ion. Question Why are alpha particles more ionising than beta or gamma radiation? Tap to flip Answer They have a bigger charge and a stronger electric field. Question What is a radioactive particle? Tap to flip Answer A particle that can decay and emit nuclear radiation. Question When is radiation emitted by a radioactive nucleus? Tap to flip Answer When the nucleus decays. Question What is radioactive decay? Tap to flip Answer A random process by which unstable nuclei emit radiation. Question Can the moment a particular unstable nucleus will decay be predicted? Tap to flip Answer No, it is impossible to predict. Question What is radioactive half-life? Tap to flip Answer The time taken for half the nuclei of a radioactive isotope to decay. Question Does the half-life of a given radioactive isotope change? Tap to flip Answer No: each radioactive isotope has its own half-life that is always the same. Question What does a decay curve show? Tap to flip Answer The pattern in radioactive decay for a large set of identical unstable nuclei. Question What is the activity of a radioactive sample, and its unit? Tap to flip Answer The number of decays per second, measured in becquerels (Bq). Question After 2 half-lives, what fraction of a radioactive isotope's amount (or activity) is left? Tap to flip Answer ¼ (½ × ½). Question After 3 half-lives, what fraction of a radioactive isotope's amount (or activity) is left? Tap to flip Answer ⅛ (½ × ½ × ½). Question How do radioactive isotopes with short half-lives emit their radiation? Tap to flip Answer They decay quickly, emitting most of their radiation over a short period of time. Question What is irradiation? Tap to flip Answer The effect of exposing an object to radiation. Question What is radioactive contamination? Tap to flip Answer The presence of unwanted radioactive atoms. Question Does a material that is irradiated become radioactive? Tap to flip Answer No. Question What is the unit of radiation dose? Tap to flip Answer The sievert (Sv). Question What does radiation dose measure? Tap to flip Answer The risk of harm from a person's exposure to radiation. Where this deck sits in the curriculum Curriculum National Curriculum for England Stage GCSE (Years 10–11) Course GCSE Physics Unit Nuclear physics Exam boards AQA, Edexcel, OCR Tiers foundation and higher England's National Curriculum sets what is taught; the units and their order are Oak National Academy's. Flash Feed is not affiliated with Oak or any exam board.
How this deck was checked On 2026-11-02, every card was compared with its source: the lessons of Oak National Academy, a public body funded by England's Department for Education that publishes lessons for the national curriculum. Because the cards come from those lessons, no second source was sought. The comparison was done automatically, not by a teacher, so a card can still be wrong. Flash Feed is not affiliated with any source named here.
Sources Total: 7 · primary: 7 · second publisher: 0
Show the other sources (5) Found a mistake? Write to support@flashfeed.app .
A Physics lesson by Oak National Academy licensed under Open Government Licence (OGL)
Flash Feed