There are several factors that affect the rate of reaction:
-The surface area available.
-Temperature
-Availability of catalyst.
-Concentration, if a/the reactant(s) is/are solutions.
-Pressure, if a/the reactants(s) is/are gases.
-Reactivity of reactants.
-Activation energy of the reaction.
catalyst
Force of gravity. The temperature of Mars. The number of ships in the harbour. The weight of a penny.
How the concentration of the reactants affects the rate of a reaction
How the concentration of the reactants affects the rate of a reaction
birth rate and death rate.
Vegetation
Concentration of reactants is one of the factors influencing the reaction rate. More the concentration, more will be the reaction rate.
The temperature of the system
climate
It depends. A higher temperature will speed up an endothermic reaction, but slow down an exothermic reaction.
temperature
Agitation affects reaction rate by increasing the amount of collisions the atoms make with one another, therefore speeding up the reaction rate.