Answer:
C. atoms are always in motion
Step-by-step explanation:
A theory of chemical combination, first stated by John Dalton in 1803. It involves the following postulates: (1) Elements consist of indivisible small particles (atoms). (2) All atoms of the same element are identical; different elements have different types of atom. (3) Atoms can neither be created nor destroyed.
Just as all matter is made up of different combinations of elements, each pure element is made up of smaller building blocks called atoms. An atom is the smallest particle of an element that still has the properties of that element.