Edexcel IGCSE Biology: Double Science 复习笔记 1.2.1 Eukaryotic Organisms Common Features of Eukaryotic Organisms: Basics All living organisms can be grouped or 'classified' using a c...
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 particle...
Background Radiation Radiation is a natural phenomenon, with radioactive elements having always existed on Earth and in outer space However, human activity has added to the amount of radiation that...
Nuclear Fusion Fusion is defined as: Small nuclides that combine together to make larger nuclei, releasing energy Low mass nuclei (such as hydrogen and helium) can undergo fusion and release energy...
Binding Energy per Nucleon Graph When comparing the stability of different nuclei, it is useful to look at the binding energy per nucleon The binding energy per nucleon is defined as: The binding e...
Atomic Mass Unit The unified atomic mass unit (u or sometimes a.m.u) is roughly equal to the mass of one proton or neutron: 1 u = 1.66 × 10−27 kg This value is provided on the exam data sheet The a...
Nuclear Binding Energy Experiments into nuclear structure have found that the total mass of a nucleus is less than the sum of the masses of its constituent nucleons This difference in mass is known...
The Hubble Constant By rearranging the equation for Hubble’s law, we can determine that the Hubble constant, H0, is: Where: v = recessional velocity of an object (km s–1) d = distance between the o...
Redshift Equation Recall the Doppler effect is defined as: The apparent change in wavelength or frequency of the radiation from a source due to its relative motion away from or toward the observer ...
