Answer:
The mass number (represented by the letter A) is defined as the total number of protons and neutrons in an atom. Consider the element helium. Its atomic number is 2, so it has two protons in its nucleus.
The atomic mass of a single atom is simply its total mass and is typically expressed in atomic mass units or amu. By definition, an atom of carbon with six neutrons, carbon-12, has an atomic mass of 12 amu.
I think it would be A because hazardous waste would most likely be found in dust, fumes etc. I'm not sure though.
<span>Chemical formula of ammonia = NH3
As we can see there are three atoms of hydrogen in one molecule of ammonia.
So in the 200 molecule of ammonia there will be = 200*3 = 600 atoms of hydrogen.
Answer - 600 atoms of hydrogen.</span>