Halogens The halogens These are the group 17 non-metals that are poisonous and include fluorine, chlorine, bromine, iodine and astatine Halogens are diatomic, meaning they form molecules of two ato...
Alkali Metals The group 1 metals The group 1 metals are called the alkali metals because they form alkaline solutions with high pH values when reacted with water Group 1 metals are lithium, sodium,...
Oxides Oxides across a period The acid-base character of the oxides provides evidence of chemical trends in the periodic table The broad trend is that oxides change from basic through amphoteric to...
Improper Algebraic Fractions What are top-heavy (improper) rational expressions (or algrbraic fractions)? The degree of the numerator is greater than or equal to the degree of the denominato...
Rational Expressions (Algebraic Fractions) What are rational expressions? Rational numbers are numbers that can be written as a fraction (quotient)Rational comes from ratio – a number is rat...
Metallic & Non-metallic Periodic trends can also be seen in the typical properties of metals and non-metals which are summarised below: The typical properties of metals and non-metals The typic...
GCSE必修科目有哪些？ GCSE或IGCSE科目众多，Edexcel GCSE提供52门考试，IGCSE有43门考试，CAIE考试局的IGCSE有70余门考试。不论是英国本土还是国内的国际学校，一般会要求学生在GCSE/IGCSE阶段学习8-10门课程。...
Electronegativity: Definition Electronegativity is the ability of an atom to attract a pair of electrons towards itself in a covalent bond This phenomenon arises from the positive nucleus’s ability...
Polynomial Factorisation What is polynomial factorisation? Factorising a polynomial combines the factor theorem with the method of polynomial division The goal is to break down a polynomial ...
