Heat quantity of a substance

The heat quantity of a substance is stored energy.
It is the energy that is contained in the small building blocks of the matter as vibration.
As the term heat "quantity" indicates, this stored energy is a quantity that we can measure in certain characteristics.

The "building blocks of matter" mentioned above form nothing more than the mass of a substance. It is obvious that a lot of these building blocks can store more energy than a few of them. From a physical point of view, a better statement is:

The heat quantity is proportional to the mass.

This is represented in the image with bodies. The bodies are all made of the same substance. The temperature is equal in all bodies. The heat quantity is indicated by Q.

The single body on the left has the simple heat quantity Q. Two equally sized bodies (centre) therefore have twice the heat quantity. The same goes for the body on the right. In the illustration the volume of the body (and hence the mass) is also doubled. This type of representation is looked at again later on.

The temperature is a measure for the vibration of the matter. If this vibration is more excited, then more energy is present. The heat quantity is greater. If no more vibrations are present in the matter, then no energy is stored. This is the case as absolute zero.

The heat quantity is proportional to the temperature.

This time the image shows two bodies of a substance with the same mass, but the second body has twice the temperature of the first body. When describing this type of temperature it is important that the absolute temperature in kelvin is chosen, since this starts at absolute zero (no heat quantity).

Different substances have different properties. Besides many obvious properties such as density, colour, odour, taste, etc. this also applies to properties that are affected by heat.

One of these properties is called "specific heat capacity". This value is a material property, which means that every substance has its own value. Different values result from the structure of matter. In engineering, heat capacity is based on the mass, as indicated by the word "specific".

The heat quantity is proportional to the specific heat capacity.

Since the term is somewhat abstract, the image first shows the relation of the density of various substances in the top left. The cubes of different materials all have the same mass m.

The substances are shown again in the bottom section, but the relation to the same heat quantity Q is applied.

The substances are:
Al: Aluminium
Fe: Iron
Pb: Lead
Au: Gold