Radium-226 is radioactive and has a half life of 1600. years. Calculate the activity of a 5.2 mg sample of radium-226. Give your answer in becquerels and in
curies. Be sure your answer has the correct number of significant digits.

A.

Answerδh > 0explanationc₆h₆  (s)  → c₆h₆ (l)if you are changing it from a solid to a liquid, you are pretty much melting the solid. this requires heat energy. therefore, the reaction is endothermic (takes in energy); the system enthalpy increases as the reaction proceeds: δh > 0.