An anthropologist finds there is so little carbon-14 remaining in a prehistoric bone that instruments cannot measure it. this means there is less than 0.2% of the amount of carbon-14 the bones would have contained when the person was alive. how long ago did the person die? (the constant for carbon-14 is 0.00012.)
answer
13,411 years
22,491 years
45,020 years
51,788 years

Malik formed a hypothesis that an increase in atmospheric oxygen levels by 10% would cause red-legged grasshoppers to grow larger than normal. suppose that malik performs an experiment to test his hypothesis. which of these actions would represent a scientific mistake in his experiment? a. he experiments on live grasshoppers instead of preserved ones. b. he focuses on red-legged grasshoppers instead of all kinds of grasshoppers. c. he varies the nitrogen and carbon dioxide levels in the air from one trial to the next. d. he conducts the experiment in a controlled lab setting with a lab partner. e. he measures the mass and length of his specimens at the start of each trial.