3. Assume that one particular atom of rhodium (Rh) has a mass of 102. Why does this number not exactly match the atomic mass of 102.91 listed on the periodic table
for this element?

What does the process of natural selection involve

One of the few xenon compounds that form is cesium xenon heptafluoride (csxef7). how many moles of csxef7 can be produced from the reaction of 13.0 mol cesium fluoride with 12.5 mol xenon hexafluoride? csf(s) + xef6(s) csxef7(s)

Ineed to find the answer of this question because i dont understand it