Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 21: Problem 7

Indicate the number of protons and neutrons in the following nuclei: (a) \({ }_{22}^{55} \mathrm{Mn},(\mathbf{b}){ }^{201} \mathrm{Hg},(\mathbf{c})\) potassium- \(39 .\)

Short Answer

Expert verified
(a) \({}_{22}^{55} \mathrm{Mn}\): 22 protons and 33 neutrons (b) \({}^{201} \mathrm{Hg}\): 80 protons and 121 neutrons (c) Potassium-39: 19 protons and 20 neutrons

Step by step solution

01

Identify the atomic number and mass number

In nuclear notation, the symbol of an atom is represented by ${ }_Z^A \mathrm{X}$, where X is the chemical symbol, Z is the atomic number (number of protons), and A is the mass number (total number of protons and neutrons). (a) \({}_{22}^{55} \mathrm{Mn}\) The atomic number (Z) is 22, and the mass number (A) is 55. (b) For \({}^{201} \mathrm{Hg}\), only the mass number is provided (A=201). We can use the periodic table to find the atomic number (Z) for mercury (Hg). (c) For potassium-39, only the mass number is provided (A=39). We can use the periodic table to find the atomic number (Z) for potassium (K).
02

Find the atomic number (Z) using the periodic table

In order to find the atomic number for mercury and potassium, consult the periodic table. For mercury (Hg), the atomic number (Z) is 80. For potassium (K), the atomic number (Z) is 19.
03

Calculate the number of protons and neutrons

We can use the formula: Number of neutrons = Mass number (A) - Atomic number (Z) (a) \({}_{22}^{55} \mathrm{Mn}\): Number of protons = Atomic number (Z) = 22 Number of neutrons = Mass number (A) - Atomic number (Z) = 55 - 22 = 33 (b) \({}^{201} \mathrm{Hg}\): Number of protons = Atomic number (Z) = 80 Number of neutrons = Mass number (A) - Atomic number (Z) = 201 - 80 = 121 (c) Potassium-39: Number of protons = Atomic number (Z) = 19 Number of neutrons = Mass number (A) - Atomic number (Z) = 39 - 19 = 20
04

Present the results

Now we have all the needed information for given nuclei. (a) \({}_{22}^{55} \mathrm{Mn}\): Number of protons = 22 Number of neutrons = 33 (b) \({}^{201} \mathrm{Hg}\): Number of protons = 80 Number of neutrons = 121 (c) Potassium-39: Number of protons = 19 Number of neutrons = 20

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 thermite reaction, \(\mathrm{Fe}_{2} \mathrm{O}_{3}(s)+2 \mathrm{Al}(s) \longrightarrow 2 \mathrm{Fe}(s)+\) \(\mathrm{Al}_{2} \mathrm{O}_{3}(s), \Delta H^{\circ}=-851.5 \mathrm{~kJ} / \mathrm{mol},\) is one of the most exother-mic reactions known. Because the heat released is sufficient to melt the iron product, the reaction is used to weld metal under the ocean. How much heat is released per mole of \(\mathrm{Fe}_{2} \mathrm{O}_{3}\) produced? How does this amount of thermal energy compare with the energy released when 2 mol of protons and 2 mol of neutrons combine to form 1 mol of alpha particles?

Cobalt- 60 , which undergoes beta decay, has a half-life of 5.26 yr. (a) How many beta particles are emitted in \(600 \mathrm{~s}\) by a \(3.75-\mathrm{mg}\) sample of \({ }^{60} \mathrm{Co} ?\) (b) What is the activity of the sample in \(\mathrm{Bq}\) ?

Charcoal samples from Stonehenge in England were burned in \(\mathrm{O}_{2},\) and the resultant \(\mathrm{CO}_{2}\) gas bubbled into a solution of \(\mathrm{Ca}(\mathrm{OH})_{2}\) (limewater), resulting in the precipitation of \(\mathrm{CaCO}_{3} .\) The \(\mathrm{CaCO}_{3}\) was removed by filtration and dried. A \(788-\mathrm{mg}\) sample of the \(\mathrm{CaCO}_{3}\) had a radioactivity of \(1.5 \times 10^{-2} \mathrm{~Bq}\) due to carbon-14. By comparison, living organisms undergo 15.3 disintegrations per minute per gram of carbon. Using the half-life of carbon- \(14,5715 \mathrm{yr},\) calculate the age of the charcoal sample.

A \(26.00-\mathrm{g}\) sample of water containing tritium, \({ }_{1}^{3} \mathrm{H},\) emits \(1.50 \times 10^{3}\) beta particles per second. Tritium is a weak beta emitter with a half-life of 12.3 yr. What fraction of all the hydrogen in the water sample is tritium?

Which of the following nuclides have magic numbers of both protons and neutrons: (a) helium- \(4,(\mathbf{b})\) oxygen \(-18,(\mathbf{c})\) calcium\(40,(\mathbf{d}) \operatorname{zinc}-66,(\mathbf{e})\) lead \(-208 ?\)
See all solutions

Recommended explanations on Chemistry Textbooks

Nuclear Chemistry

Read Explanation

Organic Chemistry

Read Explanation

Chemistry Branches

Read Explanation

The Earths Atmosphere

Read Explanation

Chemical Reactions

Read Explanation

Kinetics

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