The answer should be the third option "number of protons and neutrons." The atomic mass of a element is equal to the amount of protons, and neutrons added together in that element. So for example if we are trying to find the atomic mass of hydrogen you would add the total amount of protons and neutrons together to find it's mass although it doesn't equal the exact amount of it's mass but it's close.
Hope this helps.
Homologous structures are common structures in different species that perform different functions and may have look similar in structure.
Example- The different animals have bones that appear very similar in form and function and seem to be related.
Answer:
D. An email from a journalist to a college professor asking for an
interview
Answer:
They are in a fixed ratio
Explanation:
<span>antidiuretic hormone (ADH)</span>
