Factors Affecting Reaction Rates 
Temperature
Surface Area : increasing the surface area of a reactant will increase the reaction rate
Stirring
Concentration
Catalysts
increase of temperature
increases the exposure
Reaction Rates: the rate at which reactants change into products over time
Collisions are more likely to happen
particles react with other particles
does not get used up in reaction
number of particles in a given volume 
more reacting particles
increases opportunities for reaction 
more collisions
reaction rate is faster 
gases
particles move faster
concentration changes with pressure 
attract reacting particles towards each other
smaller particle size, larger surface area
large surface area = exposure to reactants
more collisions
more collisions, more particles react
Speeds up the reaction rate and speed
neither a reactant nor a product
written over the arrow
influences the reaction rate
faster rate of reaction
measure of hot or cold
speed up reactions
exposure of reactants to one another
lets reaction happen at a lower temperature
decrease of temperature
slows a reaction rate