/*! 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} Problem 25 (a) Define atomic number and mas... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 2: Problem 25

(a) Define atomic number and mass number. (b) Which of these can vary without changing the identity of the element?

Short Answer

Expert verified
(a) The atomic number (Z) is the number of protons in an atom's nucleus, determining its position in the periodic table and its identity. The mass number (A) is the total number of protons and neutrons in the nucleus. (b) The mass number can vary without changing the element's identity, as different isotopes have varying numbers of neutrons but the same number of protons (atomic number).

Step by step solution

01

Define Atomic Number

The atomic number, often represented by the symbol \(Z\), is the number of protons in the nucleus of an atom. The atomic number is a unique property of an element and is used to define its position in the periodic table. Each element has a specific number of protons, and therefore, a specific atomic number. For example, hydrogen has an atomic number of 1, which means it has one proton in its nucleus.
02

Define Mass Number

The mass number, often represented by the symbol \(A\), is the total number of protons and neutrons in the nucleus of an atom. The mass number does not include electrons, as their mass is negligible compared to the mass of protons and neutrons. The mass number is not unique for a specific element, as the number of neutrons can vary for atoms of the same element (known as isotopes).
03

Determine Which Can Vary Without Changing the Element's Identity

As we defined in the previous steps, the atomic number is directly related to the number of protons, which determines the element's identity. In contrast, the mass number is related to the total number of protons and neutrons. Since the number of neutrons can vary and create different isotopes of the same element, the mass number can change without impacting the element's identity. However, changing the atomic number would result in a different element due to a change in the number of protons. So, the mass number can vary without changing the identity of the element.

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

Assume that you encounter the following sentences in your reading. What is the chemical formula for each substance mentioned? (a) Sodium hydrogen carbonate is used as a deodorant. (b) Calcium hypochlorite is used in some bleaching solutions.(c) Hydrogen cyanide is a very poisonous gas. (d) Magnesium hydroxide is used as a cathartic. (e) Tin(II) fluoride has been used as a fluoride additive in toothpastes. (f) When cadmium sulfide is treated with sulfuric acid, fumes of hydrogen sulfide are given off.

Consider an atom of 10 \(\mathrm{B}\) . (a) How many protons, neutrons, and electrons does this atom contain? (b) What is the symbol of the atom obtained by adding one proton to \(^{10} \mathrm{B} ?\) (c) What is the symbol of the atom obtained by adding one neutron to 10 \(\mathrm{B}\) ? (c) What is the symbol of the atom obtained by adding one neutron to 10 \(\mathrm{B} ?(\mathbf{d})\) Are either of the atoms obtained in parts (b) and (c) isotopes of 10 \(\mathrm{B} ?\) If so which one?

The most common charge associated with scandium in its compounds is \(3+.\) Indicate the chemical formulas you would expect for compounds formed between scandium and (a) iodine, ( b) sulfur, (c) nitrogen.

Rubidium has two naturally occurring isotopes, rubidium-85 (atomic mass \(=84.9118\) amu; abundance \(=72.15 \%\) ) and rubidium-87 (atomic mass = 86.9092 amu; abundance = 27.85\(\%\) ). Calculate the atomic weight of rubidium.

Write the chemical formulas for the following compounds: (a) aluminum hydroxide, (b) potassium sulfate, (c) copper(I) oxide, ( \(\mathbf{d} )\) zinc nitrate, (e) mercury(II) bromide, (f) iron(III) carbonate, (g) sodium hypobromite.
See all solutions

Recommended explanations on Chemistry Textbooks

Ionic and Molecular Compounds

Read Explanation

The Earths Atmosphere

Read Explanation

Chemistry Branches

Read Explanation

Organic Chemistry

Read Explanation

Physical Chemistry

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.