The half life of `"_38 ^90 Sr` is 28 years. What is the disintegration rate of 15 mg of this isotope?

The half-life of is '' _38^90 Sr Is 28 years. Determine the disintegration rate of its 5 mg sample.

If the half life of radium is 1620 years then its decay constant is

Half life of .^24Na is a900 minutes.What is its decay constant?

The half life of a first order reaction is 10 years . The time taken by 10 g of the reactant to reduce its half is ______.

Radium has weight 226 and a half life of 1600 years.The umber of diintegerations produced per second from one gram are