Chemistry Unit 1 Definitions Flashcards
Precipitation Reaction
The formation of a solid from a solution during a chemical reaction.
Halogens
Group VII elements
Oxidising Agent
A reagent that oxidised another species.
Halides
Negative ions of group VII elements.
Electronegativity
The ability of an atom to attract a bonded pair of electrons in a covalent bond towards itself.
Disproportionation Reaction
The oxidation and reduction of the same element in a redox reaction.
Reducing Agent
A reagent that reduces another species.
Displacement Reaction
A reaction in which a more reactive element displaces a less reactive element from an aqueous solution in the latter’s ions.
Reducing Agent
A species that causes reduction in another species, whilst itself is being oxidised.
Oxidising Agent
A species that causes oxidation in another species, whilst itself is being reduced.
Reduction
Gain of electrons or a decrease in oxidation number.
Thermal Decomposition
The breaking up of a chemical substance with heat into at least two chemical substances.
Oxidation Number or Oxidation State
A measure of the number of electrons that an atom uses to bond with atoms of another element.
Redox Reaction
A reaction where both oxidation and reduction takes place.
Oxidation
Loss of electrons or an increase in oxidation numbers.
First Ionisation Energy
The minimum amount of energy required to remove one electron from each atom in one one mole of gaseous atoms to form 1+ ions.
Second Ionisation Energy
The minimum amount of energy required to remove one electron from each ion in one mole of gaseous 1+ ions to form 2+ ions.
Periodicity
Repeating patterns of properties across a period.
Electronegativity
The ability of an atom to attract a bonded pair of electrons in a covalent bond towards itself.
Alkali
A type of base that dissolves in water forming hydroxide (OH-)(aq) ions