I think it is amino acids
Answer:
Mass number can vary due to the fact that the number of neutrons can vary. Isotopes are named for their mass numbers. So, this element has 15 protons (atomic number), 15 electrons, and 16 neutrons (mass number minus atomic number). This isotope is phosphorus-31, which has atomic number 15.
Explanation:
It is B the only seasonal change and foxes change the color of their coat due to climate/weather changes
Morphology
Because I said so
