Which of the following has the highest value of radioactivity

Options

A. 1 g of Ra
B. 1 g of 4 `RaSO_4`
C. 1 g of `RaBr_2`
D. 1g of `Ra(HPO_4)`

Answer

A

Explanation

Radioactivity follows 1st order kinetics. So greater the concentration of radioactive nuclide, greater will be the radioactivity. Since 1g of Ra has maximum number of radioactive nuclides as compared to `1g RaSO_4 ` or `RaBr_2 ` or `Ra(HPO_4)` , so it will have the highest value of radioactivity.