Textbook Question
Identify the element represented by each of the following symbols and give the number of protons and neutrons in each: (a) 7433X
830
views
Ch.2 - Atoms, Molecules, and Ions
Brown15th EditionChemistry: The Central ScienceISBN: 9780137542970
Not the one you use?Change textbookSelect a different textbook
Table of contents
- Ch.1 - Introduction: Matter, Energy, and Measurement111
- Ch.2 - Atoms, Molecules, and Ions166
- Ch.3 - Chemical Reactions and Reaction Stoichiometry138
- Ch.4 - Reactions in Aqueous Solution127
- Ch.5 - Thermochemistry104
- Ch.6 - Electronic Structure of Atoms109
- Ch.7 - Periodic Properties of the Elements107
- Ch.8 - Basic Concepts of Chemical Bonding102
- Ch.9 - Molecular Geometry and Bonding Theories120
- Ch.10 - Gases122
- Ch.11 - Liquids and Intermolecular Forces79
- Ch.12 - Solids and Modern Materials102
- Ch.13 - Properties of Solutions99
- Ch.14 - Chemical Kinetics153
- Ch.15 - Chemical Equilibrium83
- Ch.16 - Acid-Base Equilibria109
- Ch.17 - Additional Aspects of Aqueous Equilibria117
- Ch.18 - Chemistry of the Environment60
- Ch.19 - Chemical Thermodynamics109
- Ch.20 - Electrochemistry113
- Ch.21 - Nuclear Chemistry79
- Ch.22 - Chemistry of the Nonmetals52
- Ch.23 - Transition Metals and Coordination Chemistry57
- Ch.24 - The Chemistry of Life: Organic and Biological Chemistry7
Brown15th EditionChemistry: The Central ScienceISBN: 9780137542970Not the one you use?Change textbook
Chapter 2, Problem 94a
The natural abundance of 3He is 0.000137%. (a) How many protons, neutrons, and electrons are in an atom of 3He?
Verified step by step guidance1
3He is an isotope of helium, where the superscript '3' indicates the mass number, which is the sum of protons and neutrons in the nucleus.
Helium (He) is element number 2 on the periodic table, which means it has 2 protons. The number of protons defines the element.
In a neutral atom, the number of electrons equals the number of protons. Therefore, a 3He atom also has 2 electrons.
To find the number of neutrons, subtract the number of protons from the mass number: Neutrons = Mass number - Protons = 3 - 2.
Thus, a 3He atom has 2 protons, 1 neutron, and 2 electrons.
Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
2mWas this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Atomic Structure
An atom consists of three main subatomic particles: protons, neutrons, and electrons. Protons are positively charged and reside in the nucleus, while neutrons are neutral particles also found in the nucleus. Electrons are negatively charged and orbit the nucleus in electron shells. The number of protons defines the element, while the number of neutrons can vary, leading to different isotopes.
Recommended video:
Guided course
02:10
Atom Structure
Isotopes
Isotopes are variants of a particular chemical element that have the same number of protons but different numbers of neutrons. For example, helium-3 (³He) has two protons and one neutron, distinguishing it from the more common helium-4 (⁴He), which has two neutrons. The natural abundance of isotopes can affect their occurrence and applications in various fields, including nuclear science.
Recommended video:
Guided course
04:36Isotopes
Elemental Composition
The elemental composition of an atom is determined by its atomic number, which is the number of protons in the nucleus. For helium, the atomic number is 2, indicating it has two protons and, in a neutral atom, two electrons. The number of neutrons can be calculated by subtracting the atomic number from the mass number, which for ³He is 3, resulting in one neutron.
Recommended video:
Guided course
04:19Matter Composition
Related Practice
Textbook Question
Suppose a scientist repeats the Millikan oil-drop experiment but reports the charges on the drops using an unusual (and imaginary) unit called the warmomb (wa). The scientist obtains the following data for four of the drops: Droplet Calculated Charge (wa) A 3.84⨉10−8 B 4.80⨉10−8 C 2.88⨉10−8 D 8.64⨉10−8 (b) From these data, what is the best choice for the charge of the electron in warmombs?
804
views
1
comments
Textbook Question
The nucleus of 6Li is a powerful absorber of neutrons. It exists in the naturally occurring metal to the extent of 7.5%. In the era of nuclear deterrence, large quantities of lithium were processed to remove 6Li for use in hydrogen bomb production. The lithium metal remaining after removal of 6Li was sold on the market. (b) The atomic masses of 6Li and 7Li are 6.015122 and 7.016004 u, respectively. A sample of lithium depleted in the lighter isotope was found on analysis to contain 1.442% 6Li. What is the average atomic weight of this sample of the metal?
935
views
Textbook Question
Suppose a scientist repeats the Millikan oil-drop experiment but reports the charges on the drops using an unusual (and imaginary) unit called the warmomb (wa). The scientist obtains the following data for four of the drops: Droplet Calculated Charge (wa) A 3.84⨉10−8 B 4.80⨉10−8 C 2.88⨉10−8 D 8.64⨉10−8 (d) What is the conversion factor between warmombs and coulombs?
1459
views
Textbook Question
The natural abundance of 3He is 0.000137%. (b) Based on the sum of the masses of their subatomic particles, which is expected to be more massive, an atom of 3He or an atom of 3H (which is also called tritium)?
906
views
Textbook Question
Suppose a scientist repeats the Millikan oil-drop experiment but reports the charges on the drops using an unusual (and imaginary) unit called the warmomb (wa). The scientist obtains the following data for four of the drops: Droplet Calculated Charge (wa) A 3.84⨉10−8 B 4.80⨉10−8 C 2.88⨉10−8 D 8.64⨉10−8 (c) Based on your answer to part (b), how many electrons are there on each of the droplets?
846
views