IB DP Physics: SL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 Too many neutrons Decays through ...
IB DP Physics: SL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: SL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: SL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: SL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: SL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 = ...
IB DP Physics: SL复习笔记7.1.1 Discrete Energy Levels
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...
IB DP Physics: SL复习笔记6.2.3 Gravitational Field Strength
Gravitational Field Strength There is a universal force of attraction between all matter with mass This force is known as the ‘force due to gravity’ or the weight The Earth’s gravitational field is...
IB DP Physics: SL复习笔记6.2.2 Circular Orbits
Circular Orbits Since most planets and satellites have a near circular orbit, the gravitational force FG between the sun or another planet provides the centripetal force needed to stay in an orbit ...
2022年7月31日托福考试考情回顾！
7月31日的托福考试虽然整体难度还不算高，但很明显比之前两次托福考试难度要高一些，不仅口语出现了全新话题，写作也出现了新题目，让考生分手难题提升不少。8月份是暑假最后出分的机会，考场相对少一些，考试次...
AP美国史考察内容解读，应该如何备考？
相信很多中国学生对AP美国历史并不是很感兴趣，认为枯燥且难，学了也拿不上高分。但其实，作为一门“偏文”的AP科目，学好AP美国历史不仅能展示出学生的学术能力，还可体现出申请者是一个敢于挑战，全面发展的学生...
IB DP Physics: SL复习笔记6.2.1 Newton’s Law of Gravitation
Newton's Law of Gravitation The gravitational force between two bodies outside a uniform field, e.g. between the Earth and the Sun, is defined by Newton’s Law of Gravitation Recall that the mass of...
