Calculate half life of `^238 U` if 1 gram of uraninum emits `1.23 xx 10^4` alpha particles per sec.

Calculate half life of a 1st order reaction, where the rate constant of the reaction is 6.93xx10^-3 sec^-1 .

What is the half-life period of a reaction having rate constant 6.93 xx 10^(-4)" s" ?

The half life of a 1st order reaction is 200 sec. Calculate the rate constant of the reaction.