Question
Question: Radon (Ra) decays into Polonium (\(P_{0}\)) by emitting an \(\alpha -\)particle with half-life of 4 ...
Radon (Ra) decays into Polonium (P0) by emitting an α−particle with half-life of 4 days. A sample contains 6.4×1010atoms ofRn. After 12 days, the number of atoms of Rnleft in the sample will be.
A
3.2×1010
B
0.53×1010
C
2.1×1010
D
0.8×1010
Answer
0.8×1010
Explanation
Solution
In the given case, 12 days = 3 half lives Number of atoms left after 3 half lives.
=6.4×1010×231=0.8×1010