An experiment requires that enough C2H6O be used to yield of oxygen . How much C2H6O must be weighed out?

the old alchemists made significant contributions to science even though there starting premises were off a bit. their conclusions after failure would steer them into better directions for investigation. science is no more than close observation and the initial mistakes result in rethinking and retrying experiments.

c is the answer because when something is left after something evaporates that shows the chemical change.

they it depends on if one believes about radioactivity, they make a geiger counter beep but maybe it was going to beep anyway electronics do wierd things all the time or it was programmed to beep near certain metals.