Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 42: Q.49 (page 1237)

137 Cs is a common product of nuclear fission. Suppose an accident spills 550 mCi of 137 Cs in a lab room.

a. What mass of 137 Cs is spilled?

b. If the spill is not cleaned up, how long will it take until the radiation level drops to an acceptable level, for a room this size, of 25 mCi?

Short Answer

Expert verified

Number of atom is,

N0=R0rHereR0isinitilandrisfinaldecayrateand,r=In2t12Heret12ishalftime

Step by step solution

01

Convert Ci to Bq

1Ci= 3.7x1010 Bq

so,

R0=550mCi=(550mCi)10-3Ci1mCi3.7x1010decay/sec1Ci=20.35x109decay/sec

And final decay rate of 137Cs is calculated as follows,

Substitute 30 year for t1/2 from Appendix C in above final rate equation.

r=7.32x10-10decysN0=2.8x1019atoms

Here is the mass of uranium 6.32x10-6kg

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.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

The plutonium isotope 239 Pu has a half-life of 24,000 years and decays by the emission of a 5.2 MeV alpha particle. Plutonium is not especially dangerous if handled because the activity is low and the alpha radiation doesn’t penetrate the skin. However, there are serious health concerns if even the tiniest particles of plutonium are inhaled and lodge deep in the lungs. This could happen following any kind of fire or explosion that disperses plutonium as dust. Let’s determine the level of danger. a. Soot particles are roughly 1 mm in diameter, and it is known that these particles can go deep into the lungs. How many atoms are in a 1.0@mm@diameter particle of 239 Pu? The density of plutonium is 19,800 kg/m3 . b. What is the activity, in Bq, of a 1.0@mm@diameter particle? c. The activity of the particle is very small, but the penetrating power of alpha particles is also very small. The alpha particles are all stopped, and each deposits its energy in a 50@mm@diameter sphere around the particle. What is the dose, in mSv/year, to this small sphere of tissue in the lungs? Assume that the tissue density is that of water. d. Is this exposure likely to be significant? How does it compare to the natural background of radiation exposure?

Consider the atoms O16,O18,F18,Ne18,and N20e. Some of the following questions may have more than one answer. Give all answers that apply.

a. Which are isotopes?

b. Which are isobars?

c. Which have the same chemical properties?

d. Which have the same number of neutrons?

How many half-lives must elapse until (a) 90% and (b) 99% of a radioactive sample of atoms has decayed?

The half-life of the uranium isotope U235is 700million years. The earth is approximately localid="1650486537957" 4.5billion years old. How much more U235was there when the earth formed than there is today? Give your answer as the then-to-now ratio.

a. How do we know the strong force exists?

b. How do we know the strong force is short range?
See all solutions

Recommended explanations on Physics Textbooks

Electricity and Magnetism

Read Explanation

Geometrical and Physical Optics

Read Explanation

Famous Physicists

Read Explanation

Electricity

Read Explanation

Electrostatics

Read Explanation

Classical Mechanics

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free