5-Why did Rich McCrea feel excited after finding a dinosaur bone in Tumbler Ridge? *
because it is rare to find dinosaur bones and footprints in the same spot
because the dinosaur bone provided evidence of a new kind of dinosaur
because it was the first time that he had seen a dinosaur bone in person
Obecause it helped scientists discover dinosaur trackways in the area

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.