Electrons and orbitals are an important part of chemistry, unless something is an ion the atomic number is the number of electrons. I would say atomic numer is more important.
well basically put it this way... carbon has different kinds of atomic mass, one is 14, one is 12 and some are other number. 14 is the most reactive one among all the isotopes of carbon. so therefore, atomic mass is important in chemical reaction in elements
Gamecubesupreme is wrong. love_joyously is wrong. To both of you: please do not answer questions when you are not sure your answer is correct.
The atomic mass is almost completely irrelevant in almost all chemical reactions. The number of valence-shell electrons (determined by the atomic number) is by FAR the most important chemical property of an element.