1. Water (H₂O): The smallest molecule in the list, consisting of only three atoms.

2. NaCl (Sodium Chloride): This is an ionic compound, not a molecule, but it's still relatively small. It consists of one sodium (Na) ion and one chloride (Cl) ion.

3. Glucose (C₆H₁₂O₆): A simple sugar with a relatively small molecular size.

4. Sucrose (C₁₂H₂₂O₁₁): A disaccharide made up of glucose and fructose. Larger than glucose.

5. Starch: This is a complex carbohydrate composed of many glucose monomers linked together. It has a much larger molecular size than any of the others.

Therefore, the final order from smallest to largest is:

1. Water (H₂O)

2. NaCl (Sodium Chloride)

3. Glucose (C₆H₁₂O₆)

4. Sucrose (C₁₂H₂₂O₁₁)

5. Starch