What is the average atomic mass of uranium to the nearest hundredth of an atomic mass unit?

• A. 236.50 u
• B. 240.00 u
• C. 235.00 u
• D. 238.03 u

Answer: (D)

Verified step by step guidance

1. Identify the isotopes of uranium involved and their respective atomic masses and natural abundances. For uranium, the main isotopes are typically Uranium-234, Uranium-235, and Uranium-238, each with a specific atomic mass and percentage abundance in nature.
2. Convert the percentage abundances of each isotope into decimal form by dividing by 100. This will allow you to use them as fractional weights in the calculation.
3. Use the formula for average atomic mass: \[\text{Average Atomic Mass} = \sum (\text{fractional abundance} \times \text{isotope mass})\] This means you multiply each isotope's mass by its fractional abundance and then add all these products together.
4. Perform the multiplication for each isotope and sum all the results to get the weighted average atomic mass of uranium.
5. Round the final result to the nearest hundredth of an atomic mass unit as requested.