An explosion that occurs at the end of a massive star's life is a ?
a is a large cloud of gas and dust in space.
a low- or medium-mass star becomes a at the end of its life.
a appears to emit regular bursts of radio waves.
a forms from the leftover material from a supernova; it may contain as much as three times the mass of the sun.

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