Answer: B:17,190 years
Explanation: After 5730 years ( first half life) 70 /2 = 35 mg decays and 35 g remains left. After another 5730 years ( two half lives or 11460 years) 35 /2 = 17.5mg decays and 17.5 g remains left . After another 5730 years ( three half lives or 17190 years) 17.5 /2 = 8.75mg decays and 8.75g remains left.
i know this is off topic but, can you go to my quetions, to see if you can answer any?(or if you know anyone who can answer them)
