Melting and freezing are both physical changes, which are often easy to reverse. To reverse this process, the water would need to be cooled enough until it freezes back into ice. This works because ...

For example, the formula H 2 O shows that a water molecule contains two hydrogen atoms and one oxygen atom.

Students learn to define and identify organic compounds. Chemical Reactions: Writing Molecular Formulas and an Introduction to Organic Molecules: Students learn to define and identify organic ...