Q=mcΔt is the equation for specific heat. Specific heat is the amount of heat per unit of mass that is needed to raise the temperature of the substance by 1 degree Celsius.
Different substances have different specific heats since they require differing amounts of energy to change temperature by 1 degree Celsius. Q represents the heat added, c is the specific heat of the substance, m is the mass of the sample, and Δt (delta t) is the change in temperature. This equation does not work if the substance changes states at that temperature because then energy is gained or lost by the change of state. An example of a state change is water going from solid to liquid form.