What’s a good astronomy class for students studying to be a astronomer(in or out school)

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?

One nanometer is equal to how many meters?

Rays from the sun are not considered matter true or false