. Na-24 has a half-life of 15 hours. How much of a 20.0 g sample would remai fter decaying for 60 hours?

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

Can you help me with this problem.

**Question 1:** Na-24 has a half-life of 15 hours. How much of a 20.0 g sample would remain after decaying for 60 hours?

This question involves calculating the remaining quantity of a radioactive isotope, Na-24, over a period of time by using its half-life. The half-life represents the time it takes for half of the sample to decay.

**Explanation:**
- **Half-life of Na-24:** 15 hours
- **Initial mass of sample:** 20.0 g
- **Time elapsed:** 60 hours

To solve, we determine how many half-life periods occur in the given time:
1. \( \text{Number of half-lives} = \frac{\text{Total time}}{\text{Half-life}} = \frac{60 \text{ hours}}{15 \text{ hours}} = 4 \)

Then, calculate the remaining mass:
1. After 1 half-life: \( 20.0 \, \text{g} \div 2 = 10.0 \, \text{g} \)
2. After 2 half-lives: \( 10.0 \, \text{g} \div 2 = 5.0 \, \text{g} \)
3. After 3 half-lives: \( 5.0 \, \text{g} \div 2 = 2.5 \, \text{g} \)
4. After 4 half-lives: \( 2.5 \, \text{g} \div 2 = 1.25 \, \text{g} \)

**Final Answer:** 1.25 grams of the Na-24 sample would remain after 60 hours.
Transcribed Image Text:**Question 1:** Na-24 has a half-life of 15 hours. How much of a 20.0 g sample would remain after decaying for 60 hours? This question involves calculating the remaining quantity of a radioactive isotope, Na-24, over a period of time by using its half-life. The half-life represents the time it takes for half of the sample to decay. **Explanation:** - **Half-life of Na-24:** 15 hours - **Initial mass of sample:** 20.0 g - **Time elapsed:** 60 hours To solve, we determine how many half-life periods occur in the given time: 1. \( \text{Number of half-lives} = \frac{\text{Total time}}{\text{Half-life}} = \frac{60 \text{ hours}}{15 \text{ hours}} = 4 \) Then, calculate the remaining mass: 1. After 1 half-life: \( 20.0 \, \text{g} \div 2 = 10.0 \, \text{g} \) 2. After 2 half-lives: \( 10.0 \, \text{g} \div 2 = 5.0 \, \text{g} \) 3. After 3 half-lives: \( 5.0 \, \text{g} \div 2 = 2.5 \, \text{g} \) 4. After 4 half-lives: \( 2.5 \, \text{g} \div 2 = 1.25 \, \text{g} \) **Final Answer:** 1.25 grams of the Na-24 sample would remain after 60 hours.
Expert Solution
steps

Step by step

Solved in 3 steps with 2 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.
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