Both natural processes and human activity are causing some of Earth's permanent bodies of ice to melt. If enough of this ice melts, it will add warm freshwater to the
northern Atlantic Ocean, where deep water currents start. What effect is this likely to
have on the circulation of ocean water around the globe?

the reaction mixture contains some ammonia, plus a lot of unreacted nitrogen and hydrogen. the mixture is cooled and compressed, causing the ammonia gas to condense into a liquid. the liquefied ammonia is separated and removed. the unreacted nitrogen and hydrogen are then recycled back into the reactor .

answers: to make sure that all of the broken pieces of tablet were added to the water, to allow for fair comparison of all three trials, with different particle sizes to avoid experimental error

the answer to this question is 3.