A molecular formula is a way to represent the number and types of atoms in a molecule. It shows the exact number of each element present, using chemical symbols and subscripts. For example, the molecular formula for water is H2O, indicating that each molecule contains two hydrogen atoms and one oxygen atom. Molecular formulas are important in chemistry because they provide essential information about the composition of substances. They help scientists understand the properties and behaviors of different compounds. For instance, the molecular formula for glucose is C6H12O6, which reveals that it consists of six carbon atoms, twelve hydrogen atoms, and six oxygen atoms.