Question

The half-life of Radium-226 is 1590 years. If a sample contains 200 mg}, how many mg will remain after 1000 years?

_________mg
Give your answer accurate to at least 2 decimal places.

Answer 1

137.11 mg

Explanation:

divide 200 mg by 2 = 100 mg

divide 100 by 1590 = 0.0628930818

multiply this by 1000 = 62.8930818

subtract 62.8930818 from 200 = 137.1069182

137.1069182 rounded to 2 decimal places is 137.11 mg

therefore, the answer is 137.11 mg