[GT.02H]One scientist kept a radioactive material in a container. After two half lives, the amount of radioactive material left in the container was 2 grams. What was the original mass of radioactive material in the container? (4 points) 3 grams
4 grams
6 grams
8 grams

Ascientist is designing an investigation to study the impact of invasive bird populations on local, native bird populations at backyard bird feeders. what population is most likely to be a control group for the investigation? amount of food number of bird feeders invasive bird populations local backyard birdfeeders without food