A material originally contained 300 kg of uranium-235. The material now contains 281 kg of lead-207. Assuming that all the lead-207 came from the uranium-235,
how old is the material?

affects the water bodies: excessive use of fertilizers causes eutrophication. the fertilizers which are used on plants affect the quality of land on which it is used, further causing erosion of soil. the fertilizers used on plants contain harmful chemical fumes which affect the environment.

. a balance and a graduated cylinder.

blank(1) interventricular foramen;