Answer:
52.068 amu
Explanation:
To calculate the average atomic mass of chromium, you have to first multiply the abundance of an isotope with its mass.
49.946 × 0.0435 = 2.173
51.941 × 0.838 = 43.527
52.941 × 0.0235 = 1.244
53.939 × 0.095 = 5.124
Next, add up all of the values, and you will get the average atomic mass.
2.173 + 45.527 + 1.244 + 5.124 = 52.068 amu
It took 380,000 years for electrons to be trapped in orbits around nuclei, forming the first atoms. These were mainly helium and hydrogen, which are still by far the most abundant elements in the universe.
Hope this will help you.
Decantation
Centrifugation
Filtration
Evaporation
its d because it all has to be balanced