If the activity of a radiacctive element drops to `frac(1)(16)th` of its inital value in 40 years. Find its half-life period.

One gram of _(88) Ra^(226) has activity of one curie .Find its half-life period.

Prove rthat the instantaneous rate of change of the activity of a radioactive substance is inversely propoertional to the square of its half-life.

A radioactive substance decays to 1//32 th initial activity in 25 days.Calculate its half life.

Radioactive disintegration is a first order reaction and its rate depends only upon the nature of nucleus and does not depend upon external factors like temperature and pressure. The rate of radioactive disintegration (Activity) is represented as -(dN)/(dt)=lambdaN Where lambda= decay constant, N= number of nuclei at time t, N_(0) =intial no. of nuclei. The above equation after integration can be represented as lambda=(2.303)/(t)log((N_(0))/(N)) Calculate the half-life period of a radioactive element which remains only 1//16 of its original amount in 4740 years: a) 1185 years b) 2370 years c) 52.5 years d) none of these

The half life period for the decomposition of a compound is 20 minutes, if its initial concentration increased two times, then its half life period is 10 minutes. Calculate order of a reaction.

A first order reaction takes 40 minutes for 20% completion. Calculate its half life period.

A radioactive substnce havig N nuclei has activity R.Write down an expressin for its half-life in terms of R and N.