If we start with 48 atoms of a radioactive substance, how many would remain after one halflife? after two half-lives? after three half-lives? after four halflives? Please I need help now

Rn in the right answer

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.