A radioactive substance has a half-life of 5 million years. What is the age of a rock in which 25% of the original radioactive atoms remain? You must show your work or explain how you came up with your answer for full credit.

You want free brainliest + free points? answer this drivers ed question and you shall receive : )) gas, food, and lodging are in rural areas. a. easily accessible b. always separated c. found everywhere d. less accessible

Two technicians are discussing oil changes. technician a says that waste oil and old filters need to be disposed of according to the law. technician b says that old filters can be returned to the parts department for a core value. which technician is correct?           a. technician a only   b. both technicians a and b   c. technician b only   d. neither technician a nor b

What might be the best time to start saving for retirement