Question

The mass of a single atom of carbon can be found by dividing the atomic mass (12.01 g) by 6.022 mc024-1.jpg 1023. Which is the mass of a single carbon atom, correctly written in scientific notation with the correct number of significant figures?. 1.99 mc024-2.jpg 10–23 g. 1.994 mc024-3.jpg 10–23 g. 2 mc024-4.jpg 10–23 g. 2.0 mc024-5.jpg 10–23 g

Answer 1

In the division of digits with significant numbers, the weakest link is always the limiter. In other words, the least number of significant digits is always followed. Both of the digits contain 4 significant digits, so the final answer should also contain 4 significant digits. The operation is shown below:

12.01 / (6.022x10^23) = 1.994x10^-23

Answer 2

The mass of one atom of carbon in the correct number of significant figures is 1.99×10-²³. There are four significant figures each in both the atomic mass of carbon (12.01 g) and Avogadro's number, so the answer must also have 4 significant figures.