- Physical Sciences
a molecule containing anything from thousands to hundreds of millions of atoms per molecule, a polymer, e.g. biological like proteins, nucleic acids or polysaccharides, or chemical like polythene
this consists of three separate layers of the Earth â the crust, the mantle and the core.
the levels of energy in which electrons move and which have fixed amounts of energy.
a chemical reaction in which heat, pressure or a catalyst is used, singly or in combination, to...