Melting water is an example of a physical change because the atoms are pulled apart to form a new substance. bonds are broken and atoms are rearranged. the identity of the substance does not change. it does not involve intermolecular forces or particle motion.

Why is it important for scientists to review and repeat the work of other scientists? 1.a scientific theory must be tested three times before it is proven. 2.the scientific method only applies to repeated experiments. 3.an experiment may have had errors that the scientists didn't recognize. 4.the results of individual scientists may be influenced by bias. 5.an experiment must be performed twice before the data can be analyzed.