Final answer:
One atom of copper is 5.25 times heavier than one atom of carbon-12. The correct answer is option c) 63/12 ×.
Step-by-step explanation:
The student asked how many times heavier one atom of copper is compared to one atom of carbon-12. The relative atomic mass of copper is given as 63. To find how many times heavier one atom of copper is compared to a carbon-12 atom, we need to divide the atomic mass of copper by the atomic mass of carbon, which is defined as exactly 12 atomic mass units. Therefore, the calculation would be:
63 ÷ 12 = 5.25 ×
So, one atom of copper is 5.25 times heavier than one atom of carbon-12, which corresponds to option c) 63/12 ×.