Chapter 1: Problem 49
Different isotopes (versions) of the same element can have very different half-lives. With \(t\) in years, the decay of plutonium- 240 is described by the formula $$Q=Q_{0} e^{-0.00011 t}$$ whereas the decay of plutonium-242 is described by $$Q=Q_{0} e^{-0.0000018 t}$$ Find the half-lives of plutonium- 240 and plutonium-242.
Short Answer
Step by step solution
Understand Half-Life Concept
Setup Equation for Plutonium-240
Solve for Half-Life of Plutonium-240
Calculate Half-Life of Plutonium-240
Setup Equation for Plutonium-242
Solve for Half-Life of Plutonium-242
Calculate Half-Life of Plutonium-242
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Radioactive Decay
- Atoms decay through various modes such as alpha decay, beta decay, and gamma decay.
- The time taken for half of a given amount of radioactive substance to decay is known as its half-life.
Plutonium Isotopes
- Plutonium-240: This isotope features a relatively shorter half-life of about 6301.34 years. Its medium half-life contributes to less long-term storage concerns compared to some other isotopes like plutonium-242.
- Plutonium-242: Known for its very long half-life of about 385,081.67 years. This characteristic makes it significant for considerations surrounding nuclear waste management, as it remains hazardous for a much longer time.
Exponential Functions
- An exponential function can be generally expressed as: \(Q = Q_0 e^{-kt}\)
- Here, \(Q_0\) is the initial quantity, \(k\) is the decay constant that determines how quickly decay occurs, and \(t\) represents time.
- The base of the natural exponential function, denoted by \(e\), is approximately equal to 2.71828.
- The formula is rearranged to find the specific time when half of the substance remains: \[t_{1/2} = \frac{\ln(0.5)}{-k}\]
- In cases like plutonium isotopes, precise knowledge of the decay constant allows scientists to accurately calculate half-life and understand how long the material remains active.