(a) The half life period of radium is 1590 yrs. After how many years will one gram of the pure element,
(i)be reduced to one centigram, (ii) lose one centigram. (b) The half life of radon is 3.8 days. After how many days will only one twentieth of radon sample be left over?
(c) 1 gm of radioactive substance takes 50 sec. to lose 1 centigram. Find its half life period?