The average atomic mass of an element takes into account the masses of its isotopes and their relative abundances. Uranium (U) has multiple isotopes, including uranium-238 (U-238) and uranium-235 (U-235), among others. To calculate the average atomic mass of uranium, you need to consider the atomic masses and the abundances of each isotope.
The atomic masses of U-238 and U-235 are approximately 238.0289 atomic mass units (amu) and 235.0439 amu, respectively.
The natural abundance of U-238 is about 99.27%, and the natural abundance of U-235 is approximately 0.72%.
To calculate the average atomic mass of uranium (U), you can use the following equation:
Average atomic mass of U = (Atomic mass of U-238 × Abundance of U-238) + (Atomic mass of U-235 × Abundance of U-235)
Plugging in the values:
Average atomic mass of U = (238.0289 amu × 0.9927) + (235.0439 amu × 0.0072)
Calculating this equation gives us:
Average atomic mass of U ≈ 238.0289 amu
Therefore, the average atomic mass of uranium with atomic number 92 is approximately 238.0289 atomic mass units (amu).