Empirical & Molecular Formulae The?molecular?formula?is the formula that shows the?number?and?type?of each atom in a molecule E.g. the molecular formula of ethanoic acid is C2H4O2 The?empirical...
Moles, Particles & Masses Since atoms are so small, any sensible laboratory quantity of substance must contain a huge number of atoms Such numbers are not convenient to work with, so using?mole...
The Mole The?Avogadro constant?(NA?or?L) is the number of particles equivalent to the relative?atomic?mass?or?molecular mass?of a substance in grams The Avogadro constant applies to atoms, molecule...
State Changes Changes of state are?physical changes?that are reversible These changes do not change the chemical properties or chemical makeup of the substances involved Vaporization?includes?evapo...
Balancing Equations A?symbol?equation is a shorthand way of describing a chemical reaction using?chemical symbols?to show the number and type of each atom in the reactants and products A?word?equat...
Elements & Compounds Elements are substances made from one kind of atom Compounds are made from two or more elements?chemically combined Elements take part in chemical reactions in which new su...
Male & Female Diagrams You should be able to?annotate diagrams?of the female and male?reproductive systems?to show the names of the different?structures You should also be able to recall the?fu...
Oestrogen & Progesterone During early development an embryo develops?embryonic?gonads?that will either become?ovaries?in females or?testes?in males The factor that determines whether the embryo...
SRY Gene In?sexual reproduction?in?humans, a sperm from a male fuses with, or fertilises, an egg from a female to form a?zygote, which then develops into an?embryo To begin with the embryo develops...
