All changes in heat, or energy, can be explained. Many of the reactions or changes we see in the world involve the conversion of energy. For example as we heat up a substance (eg. water), the amount of energy we put in should give us an exact temperature. However, this is a "perfect world" scenario, and does not occur in real life. Whenever heat is added to a substance like water, we always need to account for the energy that is going to be lost. For example, heat lost to evaporation or even the effect of measuring the temperature with a thermometer (the introduction of anything including a thermometer will affect the temperature).
During nuclear fission and fusion matter that seems to disappear but is actually converted into energy. The amount of energy (E) produced in such a reaction can be calculated using Einstein's formula for the equivalence of mass and energy: E = mc^2.
<span>is a mixture that composes of components that aren't uniform or they have localized regions that all have different properties. Despite the term appearing to be highly scientific, there are various common substances that are heterogeneous mixtures