AQA A Level Maths: Pure复习笔记3.2.3 Bisection of Chords
Bisection of Chords How can I find the equation of a perpendicular bisector? The perpendicular bisector of a line segment: is perpendicular to the line segment goes through the midpoint of t...
IB DP Physics: HL复习笔记7.1.9 Investigating Half-Life
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...
AQA A Level Maths: Pure复习笔记3.2.2 Finding the Centre & Radius
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 + ...
IB DP Physics: HL复习笔记7.1.8 Half-Life
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...
IB DP Physics: HL复习笔记7.1.7 Decay Equations
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...
AQA A Level Maths: Pure复习笔记3.2.1 Equation of a Circle
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 ...
AQA A Level Maths: Pure复习笔记3.1.4 Modelling with Straight Lines
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...
IB DP Physics: HL复习笔记7.1.6 Alpha, Beta & Gamma Particles
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...
IB DP Physics: HL复习笔记7.1.5 Background Radiation
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...
IB DP Physics: HL复习笔记7.1.4 Isotopes & Radioactive Decay
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...
IB DP Physics: HL复习笔记7.1.3 Emission & Absorption Spectrum
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...
IB DP Physics: HL复习笔记7.1.2 Calculating Discrete Energies
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 = ...
