Add revision topic title in here Add Big Idea 4Add Big Idea 5Add Big Idea 6 Add Big Idea 3Add Big Idea 2Add Big Idea 1 Add Key Point 1 Add Key Point 2 Add Key Point 3 How to use: 1)Write name of main revision topic on spine of fish; 2)Choose 6 Big Ideas for the topic and add these to Big Idea boxes 1-6; 3)Add 3 key points for each key idea. Top tips: 1)Use a different colour for each Big Idea; 2)Use pictures and symbols where you can 3)Use bullet points for Key points 1-3

Radioactivity Observing radiationUses of radioactivityHalf-life Gamma rays  Beta particles  Alpha particles  Helium nucleus made of 2 neutrons and 2 protons High speed electron Short wavelength radiation emitted from the nucleus Isotopes of elements have different numbers of neutrons in nucleus Alpha used for smoke alarms Time taken for the number of parent atoms in a sample to halve Large and strongly ionizing & stopped by sheet of paper Small and less ionizing & stopped by thin sheet of aluminium Wave travels long way but weakly ionizing & stopped by cm of lead Unstable radioactive nuclei become stable by emitting radiation and turn into other elements Beta used for paper thickness testing and medical tracers Time taken for count- rate to fall to half its initial level Positive charge – deflected by magnetic and electric fields Negative charge – deflected in opposite way to  in electric & magnetic fields No charge and not deflected by electric and magnetic fields Radioactive decay is random & unaffected by external conditions Gamma used for medical treatment & equipment sterilisation Half-life is the same for any sample of a particular element How to use: 1)Write name of main revision topic on spine of fish; 2)Choose 6 Big Ideas for the topic and add these to Big Idea boxes 1-6; 3)Add 3 key points for each key idea. Top tips: 1)Use a different colour for each Big Idea; 2)Use pictures and symbols where you can 3)Use bullet points for Key points 1-3 4)Handwritten is best Dr Thomson’s source : AQA Science Revision Guide