nitrate ion NO3–
carbonate ion CO32–
sulphate ion SO42–
hydroxide ion OH–,
ammonia NH4+,
zinc ion Zn2+
silver ion Ag+
mole the unit for amount of substance
the avogadro con-
stant the number of particles per mole, 6.02 × 10^23 mol–1
molar mass mass per mole, units g mol^–1
molar gas volume gas volume per mole, units dm^3 mol^–1
the simplest whole number ratio of atoms of each element
empirical formula present in a compound
the number and type of atoms of each element present in
molecular formula a compound
atoms of the same element with different numbers of neu-
isotopes trons and different masses
rela ve isotopic
mass mass compared with 1/12th the mass of carbon-12
rela ve atomic mass weighted mean mass compared 1/12th mass of carbon-12
what is the mass of
a 12C atom the standard for atomic masses
an atomic orbital is region around the nucleus that can hold up to two elec-
a trons with opposite spins
oxida on loss of electrons
reduc on gain of electrons
the electrostatic static attraction between positive and neg-
ionic bonding ative ions
the strong electrostatic attractoin between a shared pair of
covalent bonding electrons and the nuclei of the bonded atoms
average bond en-
thalpy a measurement of covalent bond strength
da ve covalent a covalent bond in which both electrons come from the
bond same atom
strong electrostatic attraction between cations and delocal-
metalic bonding ised electrons
the ability of an atom to attract the bonding electrons in a
electronega vity covalent bond