Definitions Flashcards
Isotopes
Atoms of the same element with different numbers of neutrons and different masses
Relative isotopic mass
mass compared with 1/12th mass of carbon-12
Relative atomic mass
weighted mean mass compared with 1/12th mass of carbon-12
Ionic bonding
electrostatic attraction between positive and negative ions
Covalent bond
strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms
Electronegativity
the ability of an atom to attract the bonding electrons in a covalent bond
Hydrogen bonding
intermolecular bonding between molecules containing N, O or F and the H atom of –NH, –OH or HF
First ionisation energy
removal of 1 mol of electrons from 1 mol of gaseous atoms
Disproportionation
oxidation and reduction of the same element
enthalpy change of formation
formation of 1 mol of a compound from its elements
enthalpy change of combustion
complete combustion of 1 mol of a substance
enthalpy change of neutralisation
formation of 1 mol of water from neutralisation
average bond enthalpy
as the breaking of 1 mol of bonds in gaseous molecules
homologous series
a series of organic compounds having the same functional group but with each successive member differing by CH2
structural isomers
compounds with the same molecular
formula but different structural formulae
electrophile
an electron pair acceptor
nucleophile
an electron pair donor
Relative atomic mass
the weighted mean mass of an atom compared with 1/12th mass of an atom of carbon-12
Relative isotopic mass
the mass of an atom of an isotope compared with 1/12th mass of an atom of carbon-12.
Giant covalent lattice
network of atoms bonded by strong covalent bonds (e.g. carbon (diamond, graphite and graphene) and silicon)
Heterolytic fission
when a covalent bond breaks, one bonding atom receives both electrons from the bonded pair.
Homolytic fission
when a covalent bond breaks, each bonding atom receives one electron from the bonding pair, forming 2 radicals.
