Biology: The Dynamic Science (MindTap Course List)
Biology: The Dynamic Science (MindTap Course List)
4th Edition
ISBN: 9781305389892
Author: Peter J. Russell, Paul E. Hertz, Beverly McMillan
Publisher: Cengage Learning
bartleby

Concept explainers

bartleby

Videos

Textbook Question
Book Icon
Chapter 2, Problem 1TYK

Which of the following statements about the mass number of an atom is incorrect?

a. It has a unit defined as a dalton.

b. On Earth, it equals the atomic weight.

c. Unlike the atomic weight of an atom, it does not change when gravitational forces change.

d. It equals the number of electrons in an atom.

e. It is the sum of the protons and neutrons in the atomic nucleus.

Expert Solution & Answer
Check Mark
Summary Introduction

Introduction:

The elements are made up one type of atoms which contain electrons, protons, and neutrons. The atoms contain a nucleus, which contains protons and neutrons in it. The electrons revolve around the nucleus in their orbital paths. The atomic number of an element is the total number of protons present in the nucleus.

Answer to Problem 1TYK

Correct answer:

It equals the number of electrons in an atom.

Explanation of Solution

Justification for the correct answer:

Option (d) is that it equals the number of electrons in an atom. The mass number is represented by the sum of protons and neutrons. It is taken so because the mass of a proton and a neutron is almost equal, which is 1.66×1024 g and the mass of an electron is about 1800 times lesser than this. So, it is ignored. The mass number is not equal to the number of electrons in an atom. Hence, option (d) is correct.

Justification for the incorrect answers:

Option (a) is that its unit is Dalton. The mass of proton and neutron is given by a unit named Dalton (Da). So, it is an incorrect option.

Option (b) is that on earth, it equals its atomic weight. The atomic mass is called Atomic weight if the gravitational force is considered. The mass number equals atomic weight when it is affected by the Earth’s gravitational force. So, it is an incorrect option.

Option (c) is that unlike the atomic weight of an atom, it does not change when gravitational forces change. The weight changes with a change in gravitational force but the mass is not changed. So, it is an incorrect option.

Option (e) is that it is the sum of the protons and neutrons in the atomic nucleus. The atomic nucleus contains neutron and protons, whose summation gives the mass number. So, it is an incorrect option.

Hence, options (a), (b), (c) and (e) are incorrect.

Conclusion

Thus, it can be concluded that the mass number is independent of the number of electrons contained in an atom. It is equal to the sum of the number of protons and neutrons in the atomic nucleus.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Students have asked these similar questions
Use the relationships you just described to compute the values needed to fill in the blanks in the table in Fig A1.4.1 depth (a) 1.0 cml 0.7 cml cm| base dimensions (b, c)| 1.0 cm| 1.0 cm| 1.0 cm 1.0 cm| 1.0 cm| 1.0 cm volume (V) 1.0_cm' cm'| cm'| density (p) 1.0 g/cm'| 1.0 g/cm 1.0 g/cm' mass (m)| 0.3 g Column 1: depth at 1.0 cm volume mass Column 2: depth at 0.7 cm volume mass Column 3: unknown depth depth volume
San Andreas Transform Boundary Plate Motion The geologic map below of southern California shows the position of the famous San Andreas Fault, a transform plate boundary between the North American Plate (east side) and the Pacific Plate (west side). The relative motion between the plates is indicated by the half arrows along the transform plate boundary (i.e., the Pacific Plate is moving to the northwest relative to the North American Plate). Note the two bodies of Oligocene volcanic rocks (labeled Ov) on the map in the previous page located along either side of the San Andreas Fault. These rocks are about 23.5 million years old and were once one body of rock. They have been separated by displacement along the fault. 21. Based on the offset of these volcanic rocks, what is the average annual rate of relative plate motion in cm/yr? SAF lab 2.jpg Group of answer choices 0.67 cm/yr 2 cm/yr 6.7 cm/yr 1.5 cm/yr CALIFORNIA Berkeley San Francisco K Os Q San Andreas Fault Ov…
These are NOT part of any graded assignment. Are there other examples of synapomorphy. What is it called when the traits retained are similar to ancestors?
Knowledge Booster
Background pattern image
Biology
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.
Similar questions
SEE MORE QUESTIONS
Recommended textbooks for you
Text book image
Concepts of Biology
Biology
ISBN:9781938168116
Author:Samantha Fowler, Rebecca Roush, James Wise
Publisher:OpenStax College
Text book image
Biology Today and Tomorrow without Physiology (Mi...
Biology
ISBN:9781305117396
Author:Cecie Starr, Christine Evers, Lisa Starr
Publisher:Cengage Learning
Text book image
BIOLOGY:CONCEPTS+APPL.(LOOSELEAF)
Biology
ISBN:9781305967359
Author:STARR
Publisher:CENGAGE L
Text book image
Body Structures & Functions Updated
Biology
ISBN:9780357191606
Author:Scott
Publisher:Cengage
Text book image
Biology: The Unity and Diversity of Life (MindTap...
Biology
ISBN:9781337408332
Author:Cecie Starr, Ralph Taggart, Christine Evers, Lisa Starr
Publisher:Cengage Learning
Text book image
Biology (MindTap Course List)
Biology
ISBN:9781337392938
Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. Berg
Publisher:Cengage Learning
Chemistry and the Molecules of Life; Author: Gerry Bergtrom;https://www.youtube.com/watch?v=udvppplTq1w;License: Standard YouTube License, CC-BY