Biological Molecules: Reactions A covalent bond is the sharing of two or more electrons between two atoms The electrons can be shared equally forming a nonpolar covalent bond or unequally (w...
Edexcel IGCSE Maths 复习笔记 1.16.1 Using a Calculator Why the fuss about using a calculator? GCSE Mathematics goes beyond using the basic features of a calculator and explores many of the special ...
Edexcel IGCSE Maths 复习笔记 1.15.1 Best Buy How do you tackle “Best Buy” problems? You may need a range of skills… Decide on a suitable comparison – eg total cost, cost/year, cost/m2 etc) Be consi...
Ionisation & Excitation Ionisation of an atom is: The removal, or addition, of an electron from, or to, an atom when given sufficient energy Excitation of electrons is: When an electron ...
The Electronvolt The electronvolt is a unit which is commonly used to express very small energies This is because quantum energies tend to be much smaller than 1 Joule The electronvolt is de...
The Four Fundamental Interactions There are four fundamental interactions, or fundamental forces, that exist. These are: Gravity Electromagnetism Strong Nuclear (or Strong Interaction) Weak ...
Edexcel IGCSE Maths复习笔记 1.14.1 Exchange Rates Simplifying exchange rate questions Use ratios! Put exchange rates in ratio form (use more than one line if necessary) Add lines for prices/costs U...
Baryons & Mesons Hadrons Hadrons are the group of subatomic particles that are made up of quarks Therefore, hadrons can feel the strong nuclear force There are two classes of hadrons: Ba...
Atomic Structure The atoms of all elements are made up of three types of particles: protons, neutrons and electrons. Protons and neutrons are found in the nucleus of an atom while electrons ...
