Dojo Study Club Radioactivity Notes

Radioactivity D o j o E d u c a t i o n

Chapter Overview Weightage Medium Weightage Memory-heavy Topic Similar to Chemistry - Atomic Structure 3% of 2024 Specimen Paper Concepts Nucleus Electron Cloud Atomic Structure Isotopes Nuclear Decay Alpha, Beta and Gamma Emission Half-life Nuclear Fusion and Fission

An atom consists of a positively charged nucleus made of positive protons and neutral neutrons negatively charged electrons which orbit the nucleus The mass of the electrons are negligible, hence the mass of an atom can be approximated as the mass of its nucleus. Key Concepts Atomic Structure Atoms of the same element have the same number of protons. For a given nuclide (distinct nucleus): X is the symbol of the element A is the mass (nucleon) number Z is the atomic (proton) number Nuclear Notation Isotopes are atoms of the same element that have the same number of protons (Z) but a different number of neutrons (N), resulting in a different mass number (A). Isotopes

Key Concepts Nuclear Decay is the spontaneous and random process that occurs when an unstable nucleus transitions into a more stable state by emitting radiation. It is a random process One cannot know what nucleus will decay It is a spontaneous process One cannot know when nuclear decay will occur Nuclear Decay A giant nucleus emits an alpha particle (Helium Nucleus, 2A, 2X) Alpha particles have positive charge and are relatively heavy Alpha particles have limited penetration abilities, stopped by a sheet of paper or human skin Alpha Decay Emission of a beta particle (high speed electron) High-energy, high-speed electrons emitted More penetrative than alpha particles Can be stopped by plastic, glass or a few milimeters of Aluminium Beta Decay Emission of a Gamma Photon, a form of high-energy electromagnetic radiation Electromagnetic radiation of very high frequency and energy. They are neutral and highly penetrative Requires dense materials such as lead or several centimeters of concrete to shield against them Gamma Decay

Key Concepts Nuclear Fusion is the process in which two smaller nuclei combine to form a heavier nucleus. A small amount of mass is lost, accompanied by a release of energy. Nuclear Fusion Nuclear fission is the process of splitting a nucleus into two or more smaller nuclei, along with the release of a large amount of energy. The energy produced in fission is substantial, and is the basis for nuclear power plants. Nuclear Fission

Applications Half-life is the time taken for half the radioactive nuclei in a sample to decay. It is the measure of stability of a radioactive material. The greater the half-life, the more stable the nuclei. It can be expressed through this formula. Half-Life If you’re given a table or graph with various time points and remaining amounts of radioactive sample, you can determine the half-life by identifying the time it takes for the sample to halve. Using Tables and Graphs Radioactive materials are used in treatments such as radi