What term is used to describe the healthiest lake?

Eutrophic lakes

Explanation:

Eutrophic lakes are the lakes which are in high nutrient content. The high nutrient content supports the large diversity of aquatic plants, algae and aquatic animals. The substrate of the lake is soft and muddy. This provides the suitable environment for the survival of the organisms. The organisms are generally tolerant to the low oxygen and warm temperatures.

On the basis of the above description, eutrophic lakes can be a term used to describe the healthiest lake.

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.