A scientist discovered that Earth’s outer layer is made of plates. These plates can move. The movement of these plates explains why volcanoes and earthquakes occurs and formation of mountains. Should these observations be considered evidence for a theory or law? Why?

A scientific theory is an explanation of the natural world on the basis of facts which have been repeatedly confirmed by experiments and observations. Scientific laws are rules that explain observations through either text or mathematic forms. These laws suggest cause and effect from observations and must be repeatable.

Therefore this would be a fact-supported scientific theory as it is an explanation based upon repeatedly confirmed experiments and observations, unlike Scientific law, which would be mathematical.