Edexcel IGCSE Chemistry 復(fù)習(xí)筆記 1.9.3 Writing Half-Equations Writing Half-Equations In electrochemistry we are mostly concerned with the?transfer of electrons, hence the definitions of oxid...
Edexcel IGCSE Chemistry 復(fù)習(xí)筆記 1.9.2 Electrolysis Experiments Electrolysis of Molten Compounds Lead(II) bromide is a binary ionic compound meaning that it is a compound consisting of just ...
Nuclear Radius Values The radius of some nuclei are shown in the table below: In general, nuclear radii are of the order 10–15?m or 1 fm The nuclear radius,?R, varies with nucleon number,?A?...
Closest Approach Estimate The Coulomb equation can be used to give an estimate for the radius of a nucleus When the alpha particle reaches its closest approach (to the nucleus), all of its k...
Estimating Nuclear Radius Closest Approach Method In the Rutherford scattering experiment, alpha particles are fired at a thin gold foil Some of the alpha particles are found to come straigh...
Nuclear Excited States In the same way that electrons can exist in excited states, nuclei can also exist in?excited states After an unstable nucleus emits an alpha particle, beta particle or...
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 Too many neutrons Decays through?beta-minu...
Standard Normal Distribution What is the standard normal distribution? The?standard normal distribution?is a normal distribution where the?mean is 0?and the?standard deviation is 1Why is the standa...
Nuclear Stability Graph The most common elements in the universe all tend to have values of N and Z less than 20 (plus iron which has Z = 26, N = 30) Where: N = number of neutrons Z = number...
