Investigating Half-Life Aim of the Experiment The aim of the experiment is to investigate the half-life of a decaying radioactive sample This can be done with a live sample if safe access is availa...
Finding the Centre & Radius How can I find the centre and radius from any form of the equation of a circle? A circle equation in a different form can always be rearranged into?(x-?a)2?+?...
Half-Life It is impossible to know when a particular unstable nucleus will decay But the?rate?at which the activity of a sample decreases can be known This is known as the?half-life Half-life is de...
Decay Equations Changes in N and Z by Radioactive Decay There are four reasons why a nucleus might become unstable, and these determine which decay mode will occur Decays through?beta-minus (β-) em...
Equation of a Circle What do I need to know about the equation of a circle? A circle with centre?(a,?b)?and radius?r?has the equation ?You need to be able to find the centre and radius of a ...
Modelling with Straight Lines What is modelling with straight lines? Modelling?means applying the mathematics to a?real-life?situation The model is used to?find?or?predict?future values Mode...
Alpha, Beta & Gamma Particles Some elements have nuclei that are unstable This tends to be when the number of nucleons does not balance In order to become more stable, they emit particles and/o...
Background Radiation It is important to remember that radiation is a natural phenomenon Radioactive elements have?always?existed on Earth and in outer space However, human activity has added to the...
Isotopes AZX Notation A nuclide is a group of atoms containing the same number of protons and neutrons For example, 5 atoms of oxygen are all the same nuclide but are 5 separate atoms Atomic symbol...
Emission & Absorption Spectrum Line Spectra Line spectra is a phenomenon that occurs when excited atoms emit light of certain wavelengths which correspond to different colours This comes from d...
Transitions Between Energy Levels Difference in discrete energy levels The difference between two energy levels is equal to a specific photon energy The energy (hf) of the photon is given by: ΔE?=?...
Discrete Energy Levels The Photon Model Photons are fundamental particles that make up all forms of electromagnetic radiation A photon is a massless “packet” or a “quantum” of electromagnetic energ...
