Final answer:
Approximately 0.5% of a freshly prepared sample of 19O remains after 2.00 minutes.
Step-by-step explanation:
The percentage of a freshly prepared sample of 19O that remains after 2.00 minutes can be calculated using the concept of half-life. The half-life of 19O is 29 seconds, which means that after every 29 seconds, the amount of 19O is halved. To calculate the percentage remaining after 2.00 minutes (120 seconds), we can divide the time by the half-life and use the formula:
Percentage Remaining = (1/2)(time/half-life) * 100
Substituting the values:
Percentage Remaining = (1/2)(120/29) * 100 ≈ 0.5%
Therefore, approximately 0.5% of a freshly prepared sample of 19O remains after 2.00 minutes.
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