CHAPTER XI. TRANSFORMATION PRODUCTS OF RADIUM.

= 3·8 × 10 -3 , λ 2 = 5·38 × 10 -4 , λ 3 = 4·13 × 10 -4 :—

(1) Short exposure: activity measured by β rays,

where I_T is the maximum value of the activity;

(2) Long exposure: activity measured by β rays,

where I₀ is the initial value;

(3) Any time of exposure T: activity measured by the β rays,

where

(4) Activity measured