The specific heat (capacity) c of a substance is the amount of heat Q that needs to be absorbed by a unit amount of matter to incur a unit change in temperature T. The amount of matter can be determined by several variables, namely the amount of particles N, the mass M or the volume V. It is defined starting from the heat capacity C:
cNcMcV=NC=N1T→0limΔTΔQ=MC=M1T→0limΔTΔQ=VC=V1T→0limΔTΔQ