La materia tiene masa. La masa es una propiedad característica de la materia. La masa de los cuerpos se puede determinar mediante una balanza o mediante un cronómetro, una cinta métrica y un dinamómetro.

Kepler used as his basis, both the results of his observations and those of his Astronomy professor, Tycho Brahe. You can study his three famous laws here.

The educational resource shows an interactive animation about the change of phase: solids melt when they are heated and liquids evaporate, changing to a gaseous state. If you increase the vibration of the molecules you can see how water changes phase.