<span>The
mass of an atom comes from the protons and neutrons that are found in the
nucleus. The number of protons is the atomic number of an element. To find the
number of neutrons, subtract the atomic number from the mass of an atom. So the number of neutrons are 20 (mass number) - 5 (atomic number) = 15 neutrons.</span>
In the earliest stages of development, all four organisms have a knobby head, gill slits, and a tail. These similarities tell us that all four of these organisms have a common ancestor.
Answer:
Sustainable use of the environment
Explanation:
Be it the ecosystem or the food you eat, if you just take up whatever you need instead of over exploiting the resources, another life can benefit from it. The relationship we need to form with our environment should be mutualism or commensalism but not parasitism.