can you tell from this tree whether C a position 15 evolved before or after T at position 15? Explain.

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.

the electromagnetic energy from the sun arrives in the form of visible and invisible light.

the cost of mining is extremely low compared to the money earned from mining, creating income to improve the environment.