Ocr A Level Chemistry A H432/01: Paper 1 June Final Mark Scheme Periodic Table, Elements And Physical Chemistry

mass (nucleon) number {Ans: The number of particles (protons and neutrons) in the nucleus.}standard solution {Ans: A solution of known concentration. Standard solutions are normally used in titrations to determine unknown information about another substance.}thermal decomposition {Ans: The breaking up of a chemical substance with heat into at least two chemical substances.}hydrogen bond {Ans: A strong dipole-dipole attraction between an electron-deficient hydrogen atom (O-Hδ+ or N-Hδ+) on one molecule and a lone pair of electrons on a highly electronegative atom (H-O:δ- or H-N:δ-) on a different molecule.}cation {Ans: A positively charged ion.}alkanes {Ans: The homologous series with the general formula: CnH2n+2.}giant ionic lattice {Ans: A regular three-dimensional structure of oppositely charged ions, bonded together by strong ionic bonds.}initiation {Ans: The first step in a radical substitution in which the free radicals are generated by ultraviolet radiation.}skeletal formula {Ans: A simplified organic formula, with hydrogen atoms removed from alkyl chains, leaving just a carbon skeleton and associated functional groups.}relative molecular mass, Mr {Ans: The weighted mean mass of a molecule compared with one- twelfth of the mass of an atom of carbon-12.}disproportionation {Ans: The oxidation and reduction of the same