Definitions Flashcards
Define atomic number, Z
The number of protons in the nucleus of an atom
Define mass number, A
The number of protons AND neutrons in the nucleus of an atom
Define ‘isotope’
The same number of protons but different number of neutrons in the nucleus
Define ‘ionisation energy’ and give the unit
The amount of energy required to remove one electron from each atom of one mole of atoms, to form one mole of +1 ions (kJ mol^-1)
Define Ar (relative atomic mass)
Ar = mean mass of 1 atom/ (1/12 mass of 1 atom of 12C)
Define Mr (relative molecular mass)
Mr = mean mass of 1 molecule/ (1/12 mass of 1 atom of 12C)
Define ‘empirical formula’
The simplest whole number ratio of atoms of each element in a compound
Define ‘molecular formula’
The actual number of atoms of each element in a compound
What is a ‘decomposition reaction’?
When a reactant breaks down to give two or more products
What is a ‘combination reaction’?
The reverse to decomposition - combination involves often two reactants reacting to form just one product
What is a ‘neutralisation reaction’?
When acids react with bases, they neutralise each other the products of a neutralisation reaction are neither acids nor bases
Products of neutralisation?
The products of neutralisation are a salt and water
Define ‘electrolysis’
This reaction involves the decomposition of a compound by electricity
What is a ‘precipitation’?
When a reaction involving two solutions produces an insoluble product. The product appears as a precipitate.
What is a ‘combustion reaction’?
This reaction involves the reaction of a substance with oxygen in the air.
