The number of atoms in a single molecule of starch can vary greatly depending on the specific structure and size of the molecule. Starch is a polysaccharide, which means it is made up of long chains of glucose molecules linked together. The number of glucose units in a starch molecule can range from a few hundred to several thousand, and each glucose unit contains 6 carbon atoms, 6 oxygen atoms, and 6 hydrogen atoms. Therefore, the total number of atoms in a single molecule of starch can range from several hundred to tens of thousands of atoms.