/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q.62 All the very heavy atoms found i... [FREE SOLUTION] | 91影视

91影视

Find study content
Learning Materials

Discover learning materials by subject, university or textbook.

Explanations

Textbooks
All Subjects

Anthropology

Archaeology

Architecture

Art and Design

Bengali

Biology

Business Studies

Greek

Chemistry

Chinese

Combined Science

Computer Science

Economics

Engineering

English

English Literature

Environmental Science

French

Geography

German

History

Hospitality and Tourism

Human Geography

Italian

Japanese

Law

Macroeconomics

Marketing

Math

Media Studies

Medicine

Microeconomics

Music

Nursing

Nutrition and Food Science

Physics

Polish

Politics

Psychology

Religious Studies

Sociology

Spanish

Sports Sciences

Translation

All Subjects

Biology

Business Studies

Chemistry

Combined Science

Computer Science

Economics

English

Environmental Science

Geography

History

Math

Physics

Psychology

Sociology
Features
Features

Discover all of these amazing features with a free account.

Flashcards

91影视 AI

Notes

Study Plans

Study Sets
What鈥檚 new?

Flashcards
Study your flashcards with three learning modes.

Study Sets
All of your learning materials stored in one place.

Notes
Create and edit notes or documents.

Study Plans
Organise your studies and prepare for exams.
91影视
Discover

All the hacks around your studies and career - in one place.

Find a degree

Magazine
Featured

Magazine
Trusted advice for anyone who wants to ace their studies & career.

The largest student job board with the most exciting opportunities.

Verified student deals from top brands.

Discover our mobile app to take your studies anywhere.

Learning Materials

Features

Discover

Chapter 42: Q.62 (page 1238)

All the very heavy atoms found in the earth were created long ago by nuclear fusion reactions in a supernova, an exploding star. The debris spewed out by the supernova later coalesced into the gases from which the sun and the planets of our solar system were formed. Nuclear physics suggests that the uranium isotopes 235 U and 238 U should have been created in roughly equal numbers. Today, 99.28% of uranium is 238 U and only 0.72% is 235 U. How long ago did the supernova occur?

Short Answer

Expert verified

The supernova occurred approximately $6$ billion years ago.

Step by step solution

01

Step 1. Given Information

${}^{235}U a n d {}^{238}U a r e e q u a l G i v e n b y (N 235) = (N 238)$

02

Given Expression:

$N = N o {(\frac{1}{2})}^{\frac{- t}{t 1 / 2}} F o r {}^{235}U t h e a b o v e c a n b e w r i t t e n N 238 = (N 235) {(\frac{1}{2})}^{\frac{- t}{t 1 / 2}}$

03

Given Expression:

$\frac{N_{238}}{N_{235}} = \frac{{(N_{238})}_{0 (\frac{1}{2})}^{\frac{- t}{t {(\frac{1}{2})}_{235}}}}{{(N_{238})}_{0 (\frac{1}{2})}^{\frac{- t}{t (\frac{1}{2}) 8}}} 137.9 = (\frac{1}{2})$

04

Given Expression:

$t = \frac{7.13}{(\frac{1}{(4.47 x 10^{9} y r)} - \frac{1}{(7.04 x 10^{9} y r)})} = 5.9 x 10^{9} y r$

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 91影视!

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

Use the potential-energy diagram in Figure $42.8$ to estimate the strength of the strong force between two nucleons separated by $1.5$ fm.

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

The uranium isotope ${}^{238}U$ is naturally present at low levels in many soils. One of the nuclei in the decay series of ${}^{238}U$ is the radon isotope ${}^{222}R n$ , which decays by emitting a localid="1650487447445" $5.50 M e V$ alpha particle with localid="1650487458663" $t_{1 / 2} = 3.82$ days. Radon is a gas, and it tends to seep from soil into basements. The Environmental Protection Agency recommends that homeowners take steps to remove radon, by pumping in fresh air, if the radon activity exceeds $4 p C i p e r l i t e r$ of air.

a. How many ${}^{222}R n$ atoms are there in $1 m^{3}$ of air if the activity is $4 \frac{p C i}{L}$ ?

b. The range of alpha particles in air is $鈮� 3 c m$ . Suppose we model a person as a $180 - c m$ -tall, $25 - c m$ -diameter cylinder with a mass of $65 k g$ . Only decays within $3 c m$ of the cylinder can cause exposure, and only $鈮� 50 %$ , of the decays direct the alpha particle toward the person. Determine the dose in $m S v p e r y e a r$ for a person who spends the entire year in a room where the activity is $4 p C i / L$ .

c. Does the EPA recommendation seem appropriate? Why?

Could a $56 Fe$ nucleus fission into two $28 Al$ nuclei? Your answer, which should include some calculations, should be based on the curve of binding energy.

How many protons and how many neutrons are in $(a) {}^{3}{He}, (b) {}^{32}P, (c) {}^{32}S, and (d) {}^{238}U ?$

See all solutions

Recommended explanations on Physics Textbooks

Wave Optics

Read Explanation

Thermodynamics

Read Explanation

Rotational Dynamics

Read Explanation

Solid State Physics

Read Explanation

Fluids

Read Explanation

Astrophysics

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.