Question

The robotic lander Philae landed on a comet and reported the following data from mass spectroscopic analysis of molybdenum:

Isotope Mass Relative Abundance
Mo-100 99.9 40.0%
Mo-97 96.9 60.0%
What is the average atomic mass for Mo on the comet?

Answer 1

To calculate the average atomic mass of Mo on the comet, multiply each isotope's mass by its relative abundance and add the results together, yielding an average atomic mass of 98.1 amu.

Step-by-step explanation:

To calculate the average atomic mass of molybdenum (Mo) on a comet using the given isotopic data, you would use the relative abundances and the masses of the isotopes. The formula to use is:

average atomic mass = (mass of isotope 1 × relative abundance of isotope 1) + (mass of isotope 2 × relative abundance of isotope 2)

For Mo-100 and Mo-97, the calculation would be as follows:

average atomic mass = (99.9 amu × 0.40) + (96.9 amu × 0.60)

average atomic mass = (39.96 amu) + (58.14 amu)

average atomic mass = 98.1 amu

Therefore, the average atomic mass for Mo on the comet is 98.1 atomic mass units (amu).