OCR Chemistry definitions - Module 2 0.0 / 5 ? ChemistryFoundations in chemistryA2/A-levelOCR Created by: manpandanCreated on: 25-04-17 23:04 Isotopes Atoms of the same element with different numbers of neutrons and different masses 1 of 17 Relative isotopic mass The mass of an isotope compared to 1/12th of the mass of an atom of carbon-12 2 of 17 Relative atomic mass The weighted mean mass of an atom of an element compared to 1/12th the mass of an atom of carbon-12 3 of 17 Amount of substance A quantity that measures the size of entities 4 of 17 Mole The amount of a substance that contains 6.02x10^23 particles 5 of 17 Avogadro constant The number of particles in each mole of carbon-12 (6.02x10^23) 6 of 17 Molar mass, M The mass per mole of a substance, gmol^-1 7 of 17 Molar gas volume, Vm The volume per mole of gas molecules at a stated temperature and pressure 8 of 17 Anhydrous Containing no water molecules 9 of 17 Hydrated salt A crystalline structure containing water molecules 10 of 17 Water of crystallisation Water molecules that are bonded into a crystalline structure of a compound 11 of 17 Orbital A region around the nucleus that can hold up to 2 electrons, with opposite spins 12 of 17 Ionic bonding The electrostatic attraction between positive cations and negative anions 13 of 17 Covalent bonding The strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms 14 of 17 Average bond enthalpy The average enthalpy change that takes place when breaking 1 mol of a given type of bond in the molecules of a gaseous species by homolytic fission 15 of 17 Electronegativity The ability of an atom to attract the bonding electrons in a covalent bond 16 of 17 Hydrogen bonding The intermolecular bonding between a lone pair of electrons on a molecule containing N, O or F and the H atom of -NH, -OH or HF 17 of 17
Comments
No comments have yet been made