Help, timed assignment

Ibeg i need 20. a reaction produces 4.93 l of oxygen, but was supposed to produce 1 mol of oxygen. what is the percent yield?

Listenbase your answer to the question on the information below.nuclear radiation is harmful to living cells, particularly to fast-growing cells, such as cancer cells and blood cells. an external beam of the radiation emitted from a radioisotope can be directed on a small area of a person to destroy cancer cells within the body.cobalt-60 is an artificially produced radioisotope that emits gamma rays and beta particles. one hospital keeps a 100.0-gram sample of cobalt-60 in an appropriate, secure storage container for future cancer treatment.which choice represents the correct product for the beta decay of the co-60? fe-60ni-60fe-61ni-61

Which of the following is a physical change? a.burning a piece of wood b.sawing a piece of wood in half c.rust forming on an iron fence d.a copper roof changing color from orange to green