Which statement correctly describes why a compound is a pure substance?

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?

What characteristics does a earthquake have

Gene expression control that occurs during the generation of rna is a. controlled at transcription b. control before transcription c. controlled after transcription d. controlled after translation