A radioactive isotope has a half-life of 12.0 seconds. How much of a 100 gram sample is left after 36 seconds?

Chemistry
10th Edition
ISBN:9781305957404
Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Chapter1: Chemical Foundations
Section: Chapter Questions
Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...
icon
Related questions
Question
100%
**Radioactive Decay Problem:**

A radioactive isotope has a half-life of 12.0 seconds. How much of a 100 gram sample is left after 36 seconds?

**Solution:**

To determine how much of the sample is left after a certain period, we need to calculate how many half-lives have passed. 

1. **Calculate the number of half-lives:**
   \[
   \text{Number of half-lives} = \frac{\text{total time}}{\text{half-life}}
   \]
   Given:
   - Total time = 36 seconds
   - Half-life = 12.0 seconds
   \[
   \frac{36 \text{ seconds}}{12 \text{ seconds}} = 3 \text{ half-lives}
   \]

2. **Calculate the remaining amount of the isotope:**
   
   Each half-life reduces the amount of the substance by half.
   - After 1 half-life: 
     \[
     \frac{100 \text{ grams}}{2} = 50 \text{ grams}
     \]
   - After 2 half-lives:
     \[
     \frac{50 \text{ grams}}{2} = 25 \text{ grams}
     \]
   - After 3 half-lives:
     \[
     \frac{25 \text{ grams}}{2} = 12.5 \text{ grams}
     \]

**Conclusion:**

After 36 seconds, 12.5 grams of the 100 gram sample of the radioactive isotope will remain.
Transcribed Image Text:**Radioactive Decay Problem:** A radioactive isotope has a half-life of 12.0 seconds. How much of a 100 gram sample is left after 36 seconds? **Solution:** To determine how much of the sample is left after a certain period, we need to calculate how many half-lives have passed. 1. **Calculate the number of half-lives:** \[ \text{Number of half-lives} = \frac{\text{total time}}{\text{half-life}} \] Given: - Total time = 36 seconds - Half-life = 12.0 seconds \[ \frac{36 \text{ seconds}}{12 \text{ seconds}} = 3 \text{ half-lives} \] 2. **Calculate the remaining amount of the isotope:** Each half-life reduces the amount of the substance by half. - After 1 half-life: \[ \frac{100 \text{ grams}}{2} = 50 \text{ grams} \] - After 2 half-lives: \[ \frac{50 \text{ grams}}{2} = 25 \text{ grams} \] - After 3 half-lives: \[ \frac{25 \text{ grams}}{2} = 12.5 \text{ grams} \] **Conclusion:** After 36 seconds, 12.5 grams of the 100 gram sample of the radioactive isotope will remain.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps with 1 images

Blurred answer
Knowledge Booster
Nuclear Reactions
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
Chemistry
Chemistry
Chemistry
ISBN:
9781305957404
Author:
Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:
Cengage Learning
Chemistry
Chemistry
Chemistry
ISBN:
9781259911156
Author:
Raymond Chang Dr., Jason Overby Professor
Publisher:
McGraw-Hill Education
Principles of Instrumental Analysis
Principles of Instrumental Analysis
Chemistry
ISBN:
9781305577213
Author:
Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:
Cengage Learning
Organic Chemistry
Organic Chemistry
Chemistry
ISBN:
9780078021558
Author:
Janice Gorzynski Smith Dr.
Publisher:
McGraw-Hill Education
Chemistry: Principles and Reactions
Chemistry: Principles and Reactions
Chemistry
ISBN:
9781305079373
Author:
William L. Masterton, Cecile N. Hurley
Publisher:
Cengage Learning
Elementary Principles of Chemical Processes, Bind…
Elementary Principles of Chemical Processes, Bind…
Chemistry
ISBN:
9781118431221
Author:
Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard
Publisher:
WILEY