Answer: The correct answer for the fill in the blank is 6.
Glucose is a monosaccharide, which is also called simple sugar. It is a significant source of energy in all living organisms. C₆H₁₂O₆ is the chemical formula of glucose. This indicates that the number of carbon atoms in glucose is six.
Glucose is a monomer of many complex sugars. Example- Glycogen is a storage polysccharide, which is formed by repeating units of glucose.