When using a hanging pan (cent-o-gram) balance, you should always start by doing what?

All of the following are part of the biosphere except

An atom with 7 protons, 6 neutrons, and 7 electrons has an atomic mass of amu. (enter a whole number.) numerical answers expected! answer for blank 1:

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?