Atoms and Reactions Glossary
Atoms basic building blocks of all matter
Atomic number the number of protons in the nucleus of the atoms of an element
Chemical formula a shorthand method of recording what elements (and in what proportions) are in a substance e.g. H2SO4
Chemical reaction a change in which new substances, with different properties, are produced
Compound pure substance containing atoms of two or more elements chemically combined in a fixed ratio
Electrons small negatively charged particles orbiting the nucleus of an atom
Element a pure substance made up of only one type of atoms
Equation a shorthand expression which tells you what substances are used up and which new ones are formed in a chemical reaction
Mass number the number of protons and neutrons in the nucleus of the atoms of an element
Mixture two or more pure substances mixed together but not chemically combined
Molecule a substance where 2 or more atoms of different elements are chemically bonded together in fixed ratios
Neutron neutral particles found in the nucleus of an atom
Nucleus positively charged centre of an atom; it contains protons and neutrons
Products new substances made as a result of a chemical reaction
Proton positively charged particles found in the nucleus of an atom
Pure substance a substance which contains only one kind of atom or molecule
Reactants substances you start with in a chemical reaction
Symbol shorthand way of writing the name of an element
Atomic number the number of protons in the nucleus of the atoms of an element
Chemical formula a shorthand method of recording what elements (and in what proportions) are in a substance e.g. H2SO4
Chemical reaction a change in which new substances, with different properties, are produced
Compound pure substance containing atoms of two or more elements chemically combined in a fixed ratio
Electrons small negatively charged particles orbiting the nucleus of an atom
Element a pure substance made up of only one type of atoms
Equation a shorthand expression which tells you what substances are used up and which new ones are formed in a chemical reaction
Mass number the number of protons and neutrons in the nucleus of the atoms of an element
Mixture two or more pure substances mixed together but not chemically combined
Molecule a substance where 2 or more atoms of different elements are chemically bonded together in fixed ratios
Neutron neutral particles found in the nucleus of an atom
Nucleus positively charged centre of an atom; it contains protons and neutrons
Products new substances made as a result of a chemical reaction
Proton positively charged particles found in the nucleus of an atom
Pure substance a substance which contains only one kind of atom or molecule
Reactants substances you start with in a chemical reaction
Symbol shorthand way of writing the name of an element