Mr Ball's Flashcards
Sub shell
A group of the same type of atomic orbitals (s, p, d or f) within a cell.
Ion
A positively or negatively charge atom or (covalently bonded) group of atoms (a molecular ion).
Polar covalent bond
A bond with a permanent dipole.
Redox reaction
A reaction in which both reduction and oxidation take place.
Molar volume
The volume per mole of a gas. The units of molar volume are dm3 mol-1. At room temperature and pressure the molar volume is approximately 24.0 dm3 mol-1.
Atomic orbital
A region within an atom that can hold up to two electrons, with opposite spins.
(Successive) Ionisation energy
A measure of the energy required to remove each electron in turn, e.g. the second ionisation energy is the energy required to remove one electron from each ion in one mole of gaseous 1+ ions to form one mole of gaseous 2+ ions.
Anion.
A negatively charged ion.
Thermal decomposition
The breaking up of chemical substance with heat into at least two chemical substances.
Oxidation
Loss of electrons or an increase in oxidation number.
Oxidising agent
A reagent that oxidises (take electrons from) another species.
(Second) ionisation energy.
The energy required to remove one electron from each ion in one mole of gaseous 1+ ions to form one moles of gaseous 2+ ions.
Oxidation number
A measure of the number of electrons that an atom uses to bond with atoms of another element. Oxidation numbers are derived from a set of rules.
Stoichiometry
The molar relationship between the relative quantities of substances taking part in a reaction.
Intermolecular force
An attractive force between neighbouring molecules. Intermolecular forces can be van der Waals’ forces (induced dipole-dipole forces), permanent dipole-dipole forces or hydrogen bonds.
Water of crystallisation
Water molecules that form an essential part of the crystallin structure of a compound.
Electron shielding
The repulsion between electrons in different inner shells. Shielding reduces the net attractive force from the positive nucleus on the outer shell electrons.
Electronegativity
A measure of the attraction of a bonded atom for the pair of electrons in a covalent bond.
Relative molecular, Mr
The weighted mean mass of a molecule compared with one twelfth of the mass of an atom of carbon-12.
Relative formula mass
The weighted mean mass of a formula unit compared with one twelfth of the mass of an atom of carbon-12.
Coordinate bond
A shared pair of electrons which has been provided by one of the bonding atoms only; also called a dative covalent bond.
(first) ionisation energy
The energy required to remove the most loosely held electron from one mole of gases atoms.
Mole
The amount of any substance containing as many particles as there are carbon atoms in exactly 12 g of the carbon-12 isotope.
Isotopes
Atoms of the same element with different numbers of neutrons and different masses.
Concentration
The amount of solute, in mol, per 1 dm3 (1000 cm3) of solution.
Compound
A substance formed from two or more chemically bonded elements in a fixed ratio, usually shown by a chemical formula.
Giant covalent lattice
A three dimensional structure of atoms, bonded together by strong covalent bonds.
Permanent dipole
A small charge difference across a bond resulting from a difference in electro-negativities of the bonded atoms.