You are discussing earthquakes with your friends. One friend states that a magnitude 8.0 earthquake is twice as powerful as a 4.0 magnitude earthquake. Another friend states that it is actually 40 times more powerful. Another friend claims that it is 10,000 times more powerful. Which friend is more correct? Explain.

The friend that says 8.0 is twice as powerful as a 4.0. Hope this helps

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.