# Calculating Number of Atoms in a Sample

## What is the correct expression to calculate the number of atoms in a sample with the correct number of significant figures?

Rita divides Avogadro’s number by 2.055 to calculate the number of atoms in a sample. Which expression gives her result to the correct number of significant figures?

**Answer:**

2.930 x 10^23 is the correct answer

When dealing with significant figures in calculations, it is important to ensure that the final result reflects the precision of the original data. In this case, Rita is dividing Avogadro’s number (approximately 6.022 x 10^23) by 2.055 to calculate the number of atoms in a sample.

The correct expression to calculate the number of atoms in a sample with the correct number of significant figures is by dividing Avogadro’s number by 2.055, resulting in 2.930 x 10^23. This answer maintains the original four significant figures from both Avogadro’s number and 2.055, providing a precise result.