ISOTOPES AND NUCLEAR RADIATION 0.0 / 5 ? PhysicsAtomic StructureGCSEAQA Created by: MissComfortCreated on: 11-05-17 18:50 All atoms of each element have a set number of what? Protons, so each nucleus has a given positive charge 1 of 34 What is and atomic number? The number of protons in an atom 2 of 34 What is the mass number (the mass of the nucleus) (is the number of protons + number of neutrons in ita nucleus) 3 of 34 What are isotopes of an element? Atoms with the same number of protons (the same atomic number) but a different number of neutrons (different mass number) 4 of 34 What else do isotopes have? the same charge on th nucleus 5 of 34 What do all elements have in common? they all have different isotopes but only 1 or 2 stable ones. 6 of 34 What do unstable isotopes do? They decay into other elements and give out radiation as they try to become more stable 7 of 34 What is radioactive decay? When unstable isotopees decay into other elements and give out radiation as they try to become more stable 8 of 34 What do radioactive substances spit out? they spit out ionising radiation (alpha, beta, gamma radiation) 9 of 34 What do radioactive substances also release? They can relase neutrons (n) when they decay, as they rebalance their atomic and mass numbers 10 of 34 What does ionising radiation do? Knocks electrons off atomss, creating positive ions 11 of 34 What is ionising power? How easily it can knock electrons off atoms which creates positive ions 12 of 34 What is alpha radiation? Its when an alpha particle (a) is emitted form the nucleus. 13 of 34 What is an a particle? It has 2 neutrons and 2 protons, like a helium nucleus 14 of 34 Do alpha particles penetrate far into materials? NO, they DON'T penetrate very far int materials and are stopped quickly 15 of 34 How many cm can alpha particles travel in air? They can only travel a few cm in air 16 of 34 What absorbs alpha particles? a sheet of paper 17 of 34 Why are alpha particles strongly ionising? Because of their size 18 of 34 Where is alpha radiation used in real life? It is used in smoke detectors 19 of 34 How is alpha radiation used in real life? It ionises air particles causing a current to flow. If there is smoke in the air, it binds to the ions, meaning the current stops and the alarm sounds 20 of 34 What is a beta particle (B) ? A fast-moving electron released by the nucleus 21 of 34 What is the mass of a beta particle? They have virtually no mass 22 of 34 What is the charge of a beta particle? -1 23 of 34 How ionising are beta particles? They are moderately ionising 24 of 34 How far do they penetrate into materials? They penetrate moderately far into materials before colliding 25 of 34 How much ar beta particles range in air? They have a range in air of a few metres 26 of 34 What are they absorbed by? A sheet of aluminium (around 5 mm) 27 of 34 What happens when a beta particle is emitted? a neutron in the nucleus has turned into a proton 28 of 34 What are gamma rays (y) ? Waves of electromagnetic (EM) radiation released by the nucleus 29 of 34 How far do they penetrate into materials withouth being stopped? They peneterate far without being stopped 30 of 34 How far do they travel through air? They will travel a long distance through air 31 of 34 Why are gamma rays weakly ionising? because they pass through rather than collide with atoms 32 of 34 What do gamma rays eventually do? Eventually they hit something and do damage 33 of 34 What can gamma rays be absorbed by? They can be absorbed by thick sheets of lead or metres of concrete 34 of 34
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