Isotope
atom of same element with different numbers of neutrons and different masses
relative isotopic mass
mass compared with 1/12th the mass of C-12
relative atomic mass
weighted mean mass compared with 1/12th mass of C-12
ionic bond
electrostatic attraction between positive and negative ions
giant ionic lattice
from oppositely charged ions strongly attracted in all directions
average bond enthalpy
measurement of strength of covalent bond, breaking of 1 mol of bonds in gaseous atoms
electronegativity
ability of an atom to attract bonding electrons in a covalent bond
periodicity
showing repeated trends in physical and chemical properties
first ionic energy
removal of 1 mol of electrons from 1 mol of gaseous atom
exothermic
releases energy: combustion
endothermic
takes in energy: thermal decomposition
enthalpy change of formation
formation of 1 mol of a compound from its elements
enthalpy change of combustion
complete combustion of 1 mol of substance
enthalpy change of neutralisation
formation of 1 mol of water from neutralisation
lattice enthalpy
1 mol of ionic lattice from gaseous ions and use as a measure of the strength of ionic bonding in a giant ionic lattice
enthalpy change of solution
dissolving of 1 mol of solute
enthalpy change of hydration
dissolving of 1 mol of gaseous ions in water
general formula
simple algebraic formula
structural formula
minimal detail that shows arrangement of atoms in a molecule
displayed formula
positioning of atoms and bonds between them
skeletal formula
organic formula shown by removing hydrogen atoms from alkyl chains: skeleton
homologous series
organic compounds that have the same functional group but each successive member is differing by CH2
structural isomer
compound with same molecular formula but different structural formula
homolytic fission
covalent bond breaks and one electron from bonded pair, goes to each atom forming two radicals
hetrolytic fission
bonding atom recieveing both electrons from one bonding pair
radical
species with an unpaired electron
curly arrow
movement of electron pair, showing hetrolytic fission or formation of covalent bond
sigma bond
overlap of orbitals directly between bonding atoms
pi bond
sideways overlap of adjacent p-orbitals above and below the bonding C atoms
sterioisomers
compounds with same structural formula with different arrangement in space
E/Z isomerism
restricted rotation about a double bond
electrophile
electron pair acceptor
nucelophile
electron pair donor
optical isomer
non-superimposable mirror image
Standard half cell
The emf of a half cell compared with a hydrogen half cell at standard conditions
Entropy
The disorder of a reaction (sum of products -sum of reactants