Which statement is a scientific claim? A. Observation of certain stars explain why humans behave the way they do B. Observations of constellations show that arts have moved over time C. Three stars in the constellation Orion look like a belt a hunter might wear D. Rhe constellation Orion is the easiest to recognize of the stars in his belt

D. Observations of constellations show that stars have moved over time.

Explanation: Constellation changes there position over time because of earth's rotation around sun. So, observation of constellations shows that stars have moved over time is a scietific claim. If stars would not move then constellation will not form.

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.