How many moles of ammonia, NH,, are contained in
6.21 x 1024 molecules of ammonia?

the atomic number will stay the same no matter how many electrons it has, so it doesn’t decrease nor increase. it’ll only change with a different number of protons

while cooking a piece of 1/2 pound beef steak, a cast iron pan (2.4kg in weight) was heated 260 celsius.

in the analysis of systems that involve fluid flow, we frequently encounter the combination of properties u and pv.