Chemistry

Average Rate
Change in volume/ time.
Rate of reaction
Rate = 1/time
Rate = 1/T
Activation Energy
The minimum kinetic energy required by colliding particles before a reaction will occur.
Enthalpy
DeltaH = cmDeltaT
Enthalpy of Solution
The energy change when one mole of a substance dissolves in water.
Enthalpy of Neutralisation
Heterogeneuous Catalyst
A catalyst of a different physical state from the reactants.
Homogeneous Catalyst
A catalyst of the same physical state from the reactants.
Going down a group in the periodic table, the atomic size/covalent radius increases because
the number of electron shells increases.
Going from left to right along a period in the periodic table, the atomic size/covalent radius decreases because
the nuclear charge increases.
Ionisation Enthalpy
The amount energy required to remove one mole of electrons from one mole of atoms. Always in the gaseous state and always an endothermic reaction.