Edexcel IGCSE Maths复习笔记 1.10.1 Rounding & Estimation
Edexcel IGCSE Maths复习笔记 1.10.1 Rounding & Estimation Why use estimation? We estimate to find approximations for difficult sums Or to check our answers are about the right size (right order ...
AQA A Level Chemistry复习笔记3.3.1 Reactivity of Halogenoalkanes
Reactivity of Halogenoalkanes The halogenoalkanes have different rates of substitution reactions Since substitution reactions involve breaking the carbon-halogen bond the bond energies can b...
AQA A Level Chemistry复习笔记3.2.1 Fractional Distillation of Crude Oil
Fractional Distillation Crude oil is currently the world's main source of organic chemicals As a mixture, it isn’t a very useful substance, but the different hydrocarbons that make up the mixture, ...
AQA A Level Chemistry复习笔记3.1.1 Functional Groups
Organic Definitions & Terminology Organic chemistry is the chemistry of carbon compounds Carbon forms a vast number of compounds because it can form strong covalent bonds with itself This enabl...
AQA A Level Chemistry复习笔记2.3.1 Physical Properties of Group 7
Group 7: Physical Properties The group 7 elements are called halogens The halogens have uses in water purification and as bleaching agents (chlorine), as flame-retardants and fire extinguish...
AQA A Level Chemistry复习笔记2.2.1 Trends in Group 2: The Alkaline Earth Metals
Group 2: Trends Chemical trends All elements in Group 2 (also called alkali earth metals) have two electrons in their outermost principal quantum shell All Group 2 metals can form ionic compounds i...
AQA A Level Chemistry复习笔记2.1.1 Classification of an Element
The Periodic Table: Structure & Classification The periodic table is a list of all known elements arranged in order of increasing atomic number, from 1 to 118. In addition to this, the elements...
AQA A Level Chemistry复习笔记1.9.1 Oxidation & Reduction
Oxidation & Reduction There are three definitions of oxidation and reduction used in different branches of chemistry Oxidation and reduction can be used to describe any of the following proces...
AQA A Level Chemistry复习笔记1.8.1 Chemical Equilibria
Reversible Reactions & Dynamic Equilibrium Reversible reaction Some reactions go to completion where the reactants are used up to form the products and the reaction stops when all of the reacta...
