Anew penny has a mass of 2.49 g and a volume of 0.349 cm3. is the penny made of pure copper?

If the atomic mass of an atom is 34 and the atom contains 13 protons, how many neutrons does the atom contain?

Which substance has non polar covalent bonds

Which of your 24 wells had indications that a chemical reaction occurred? how were you able to tell that a chemical reaction occurred? which of your 24 wells had indications that a physical reaction occurred? how were you able to tell that a physical reaction occurred? report on both mixing and evaporation. make a general statement about whether your hypotheses were validated or rejected. must your hypotheses be correct for this to be a successful laboratory?