1 gm of radium with atomic weight 226 emit 4*10^10 particles per second then t half =?

226 grams of radium is considered as 1 mole so 1 gram is considered as 1/226 moles and weknow that 1 mole o a substance contains avagrodo number of particles so 1/226 moles contains 1/226*avagardo number of particles and so in a half life time the susbstance become 50%of its initial amount so 1/226 moles becomes 1/452 moles so you have got to multiply 1//452 with avagrado’s number and divide it by 4*10^10 andd you get the half life period..........