The energy of the universe is constant. That what mentioned by the first law of thermodynamics, Does this mean that E is always equal to zero?

Mike and mitchell decide to have a foot race. they mark off a stretch of 100 yards, and recruit cindy to work the stopwatch. after running the race and looking at the results, cindy declared that mitchell was the fastest. so how did the boys times compare?

What is the rate law for the uncatalyzed reaction?

How many grams are in 68.2 molecules of br2?