The hypothesis refers to the proposed or suggested explanation for any observed phenomenon. It provides the starting point for scientific investigation after which experiments are designed and performed in order to pass or fail the hypothesis.
In contrast, a theory refers to a set of principles which are well supported by scientific experiments, pieces of evidence, and observations.
A theory is an explanation that why something occurs while the hypothesis is a prediction or guess about what will happen.
A theory is a conclusion that is given after many experiments while a hypothesis is an idea that is given before an experiment that what will happen as a result experiment.
The periodic theory explains that elements would repeat their properties repeatedly. The theory also made a hypothesis that certain elements would be discovered.
