Relative Isotopic Mass
The mass of an atom of an isotope compared with one-twelfth of the mass of an atom of carbon-12.
Relative Atomic Mass
The weighted mean mass of an atom compared with one-twelfth of the mass of an atom of carbon-12.
Relative Molecular Mass
The weighted mean mass of a molecule compared with one-twelfth of the mass of carbon-12.
First Ionisation Energy
The energy required to remove one electron from each atom in one mole of gaseous atoms.
The repulsion between electrons in different inner shells.
(Shielding reduces the overall attractive force from the positive nucleus. )
The region within an atom that can hold up to two electrons with opposite spins.
Electrostatic force of attraction between oppositely charged Ions.
(Bond between metal and non-metal)
A bond formed by a shared pair of electrons.
(Bond between non-metal and non-metal)
Where the shared pair of electrons have both been donated by the same atom.
A measure of the attraction of a bonded atom for the pair of electrons in a covalent bond.
A small charge difference across a bond as a result of the difference in electro negativities of the bonded atoms.
Polar Covalent Bond
Has a permanent dipole.
Has an overall dipole when you take into account any dipole which arises across the bonds.
An attractive force between neighbouring molecules.
Permanent Dipole-Dipole Force
A weak attractive force between permanent dipoles on neighbouring molecules.
Van der Waals' Forces
Weak attractive forces between very small temporary dipoles in neighbouring molecules.
Giant Metallic Lattice
A 3-dimensional lattice of positive ions in a 'sea' of delocalised electrons and they are bonded together by strong metallic bonding.
The electrostatic force of attraction between positive metal ions and the delocalised electrons.
Giant Covalent Lattice
A 3-dimensional lattice structure of atoms bonded together by strong covalent bonds.
Simple Covalent Lattice
A 3-dimensional structure of molecules bonded together by weak intermolecular forces.
A species which can donate a proton, H+(aq).
A species which can accept a proton, H+(aq).
A type of base which dissolves in water to give hydroxide ions, OH-(aq).
The amount of any substance containing as many particles as there are carbon atoms in exactly 12g of carbon-12 isotope.
The mass per mole of a substance. The units of molar mass are g mol^-1.
The simplest whole-number ratio of atoms of each element present in the compound.
The actual number of atoms of each element in a molecule.
A small group of atoms held together by covalent bonds.
Moles of solute / Volume of solution (dm^3) = Concentration of Solution (mol dm^3)
LOSS of electrons
GAIN of electrons
A reaction in which both oxidation and reduction take place.
A horizontal row of elements in the periodic table.
Elements show trends in properties across a period.
A vertical column in the periodic table.
Elements in a group have similar chemical properties as their atoms have the same number of outer shell electrons.
The oxidation and reduction of the same element in a redox reaction.