Moths resting on the trunks of trees often resemble the tree bark so that potential predators do not perceive them as prey. This is an example of

concealing coloration

Explanation:

Concealing coloration is when an animal's colors match with natural things in it's background, such as trees or flowers.

we would need to see the picture to answer it

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.