Final answer:
To find the number of carbon atoms in glucose, multiply the number of moles by 6 and then by Avogadro's number, rounding the result to three significant figures.
Step-by-step explanation:
To calculate the number of carbon atoms in a sample of glucose, C6H12O6, we can use Avogadro's number as a conversion factor. Since glucose has a molecular formula with 6 carbon atoms, the number of carbon atoms in one mole of glucose is 6 multiplied by Avogadro's number (6.022 × 1023 atoms/mol) .
If we have a sample with a mass of glucose, we must first convert the mass to moles by dividing by the molar mass of glucose (approximately 180 g/mol), and then apply the above multiplication for the number of carbon atoms. The result should be rounded to three significant figures, given that Avogadro's number is known to that degree of precision. For example, if we had 1.50 × 1025 carbon atoms, since this is greater than Avogadro's number, we would conclude there are more than one mole of carbon atoms in the sample.