Scientists found stone tool specimens in a cave in africa. using potassium–argon radiometric dating, they discovered that the tools contained 25 percent radioactive potassium-40. how old are the tools? (you must show your calculations to receive credit.) *the half-life for potassium-40 to argon-40 is 1.25 billion years.

Aremote community desperately needs more electrical energy. it is located in an area with the following characteristics: average wind speed of 15 – 20 km/hr some medium-sized rivers with slow-moving currents few coal deposits some oil exploration being conducted within 400 miles based on the above information, which energy source would be the most economical and safest for the community to pursue? a. fossil fuel b. hydroelectric c. nuclear d. wind