51 Cr has a half-life of 28 days. What fraction of the original sample would remain after 168 days?

Ammonium perchlorate nh4clo4 is the solid rocket fuel used by the u. s. space shuttle. it reacts with itself to produce nitrogen gas n2 , chlorine gas cl2 , oxygen gas o2 , water h2o , and a great deal of energy. what mass of nitrogen gas is produced by the reaction of 2.1g of ammonium perchlorate?

8) warming your hands by a fire is an example if which heat transfer? a. conduction b. convection c. radiation d. none of these

Abaker touches a pie right after taking it out of the oven. which statement best explains why the pie feels hot?