The half-life of sodium-25, when 1.00 gram of a 16.00-gram sample remains unchanged after 237 seconds, is approximately 59.3 seconds. This solution was found by calculating the number of times the sample halved and dividing the total time by this figure.
The question asks for the half-life of sodium-25 if 1.00 gram of a 16.00-gram sample remains unchanged after 237 seconds. In nuclear physics and nuclear chemistry, the half-life is the amount of time it takes for half of a sample of a radioactive substance to undergo decay.
Given that sodium-25 has gone from 16 grams to 1 gram, we can see that 1/16th of the original amount is left after 237 seconds. In other words, the quantity of sodium-25 has halved approximately 4 times. Therefore, the half-life will be the total time divided by the number of half-lives.
By dividing 237 seconds by 4, we get 59.25 seconds. So, the closest accurate answer is (2) 59.3s.
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B-Models only present macroscopic versions of the submicroscopic.
C-Models help explain phenomena but are not good for predicting events.
D-Models are used throughout science although they are not always accurate.
Answer : The temperature will be, 392.462 K
Explanation :
According to the Arrhenius equation,
or,
where,
= rate constant at =
= rate constant at =
= activation energy for the reaction = 66.41 kJ/mole = 66410 J/mole
R = gas constant = 8.314 J/mole.K
= initial temperature = 293 K
= final temperature = ?
Now put all the given values in this formula, we get:
Therefore, the temperature will be, 392.462 K