Answer:
0.0488 g
Explanation:
We are given
The radioisotope Fluorine-21
Half-life is 5 seconds
Initial mass of Fluorine-21 is 200 g
Time = 1 min or 60 seconds
Required to determine the New mass after decay
- We need to know that half life of a radioisotope is the time taken by a radioactive isotope to decay by half the original amount.
- To calculate the remaining mass after decay we use the formula,
New mass = Original mass × (1/2)^n , where n is the number of half lives.
In this case, n = 60 s ÷ 5 s
= 12
New mass = 200 g × (1/2)^12
= 200 g × 1/4096
= 0.0488 g
Therefore, the mass of Fluorine-21 remaining after 1 minute is 0.0488 g
