Q)
(chatquestion)...The half life of a radioactive substance is
28.
23.10 minute. If 1023 atoms of the
substance are active at any instant of
time, then the activity of the substance
will be - (in dps)
(A) 1 × 1019
(C) 5 x 1019
(B) 3 x 1019
(D) 7 × 1019
The weight based ratio of U238 and
Pb226 in a sample of rock is 4: 3. If the
half life of U238 is 4.5 × 109 years, then
29.
the
of rock is -
age
(A) 9.0 × 109
years
(B) 6.3 x 109
years
(C) 4.5 x 109 years
(D) 3.78 × 109
years
...
