Definitions (Understand)

a positively or negatively charged atom or (covalently bonded) group of atoms (a molecular ion).

the number of protons in the nucleus of an atom

the weighted mean mass of a formula unit compared with one-twelth of the mass of an atom of carbon 12

the weighted mean mass of a molecule compared with one-twelfth of the mass of an atom of carbon-12.

the amount of substance containing as many particles as there are carbon atoms in exactly 12g of carbon-12 isotope

The mass of one mole of any substance, expressed in grams per mole.

the simplest whole number ratio of atoms of each element in a compound

the number of atoms of each element in a molecule

a substance containing no water molecules

crystalline and containing water molecules

water molecules that form an essential part of the crystalline structure of a compound.

an outer-shell pair of electrons that is not involved in chemical bonding

A pair of electrons shared between two atoms to make a covalent bond.

a small charge difference across a bond resulting from a difference in the electronegativities of the bonded atoms

A covalent bond with a permanent dipole

a molecule with an overall dipole, taking into account any dipoles across bonds

an alkane with a hydrogen atom removed, e.g. CH3, C2H5; alkyl groups are often shown as R

Contains carbon atoms joined together in a ring that is not aromatic.

Contains carbon atoms joined together in straight or branched chains.

Containing one or more benzene rings

Containing single bonds only

Containing a multiple carbon-carbon bond

molecules with the same molecular formula but with different arrangements of atoms

the breaking of a covalent bond with one of the bonded electrons going to each atom, forming two radicals.