Year: 2019 Odisha
Topic: Nuclei
Time :
1. The rate of radioactive disintegration at an instant for a radioactive sample of half life2 . 2 × 10
9
s is 10
10
s
−1
. The number of radioactive atoms in that sample at that instant is
(1). 3.17×10
20
(2). 3.17×10
17
(3). 3.17×10
18
(4). 3.17×10
19