Answer: Option C.
The number of protons and neurons it's contain.
Explanation:
Mass number of an atom is also called atomic mass of an atom which is some what expressed in Dalton i.e 1/2. The mass number is the total number of protons and neutrons altogether called nucleons in an atomic nucleus.
<span>The most dominant chemolithotrophs in pelagic waters are ammonia-oxidizing archaea. The first step in nitrification is performed by ammonia oxidising microorganisms that convert ammonia into nitrite ions. Science has known about nitrifying bacteria for over a hundred years now thanks to the discovery of S. Winogradsky.</span>
You can determine that the igneous intrusion is younger than layer C, because layer C is the oldest, acknowledging the fact that it is the deepest layer.