Knowing and controlling the rate of chemical reactions is important in living cells, in the lab and in industry. We can measure the rate of a reaction by following the rate at which reactants are used up. Alternatively, we can measure the rate at which products are made. The minimum amount of energy that particles must have in order to react is called the activation energy. The rate of a chemical reaction increases if the surface area of any solid reactants is increased. Reactions happen more quickly as the temperature increases. A 10ºC increase in temperature from room temperature roughly doubles the rate of reaction. The rate of a chemical reaction increases with temperature because the particles collide more often and they have more energy. Increasing the concentration of reactants increases the frequency of collisions between particles, increasing the rate of reaction.