Barron's Science 360: A Complete Study Guide to Chemistry with Online Practice

Mark Kernion, Joseph A. Mascetta

• Publisher: Barrons Educational Services
• Year: 2021
• ISBN:
  9781506281438
• Topic: Biological Sciences
• Subtopic: Science General
• Index: Biological Sciences

Barron's Science 360: Chemistry is your complete go-to guide for everything chemistry This comprehensive guide is an essential resource for:

• High school and college courses
• Homeschooling
• Virtual Learning
• Learning pods

Inside you'll find:

• Comprehensive Content Review: Begin your study with the basic building block of chemistry and build as you go. Topics include, atomic structure, chemical formulas, electrochemistry, the basics of organic chemistry, and much more.
• Effective Organization: Topic organization and simple lesson formats break down the subject matter into manageable learning modules that help guide a successful study plan customized to your needs.
• Clear Examples and Illustrations: Easy-to-follow explanations, hundreds of helpful illustrations, and numerous step-by-step examples make this book ideal for self-study and rapid learning.
• Practice Exercises: Each chapter ends with practice exercises designed to reinforce and extend key skills and concepts. These checkup exercises, along with the answers and solutions, will help you assess your understanding and monitor your progress.
• Access to Online Practice: Take your learning online for 50 practice questions designed to test your knowledge with automated scoring to show you how far you have come.

PART I

AN INTRODUCTION

1 INTRODUCTION TO CHEMISTRY

WHAT YOU WILL LEARN

Upon completing this chapter, you will be able to:

•Identify types of matter as elements, compounds, or mixtures

•Identify chemical and physical properties and changes

•Explain how energy is involved in chemical and physical changes

•Identify and use the SI system of measurement

•Do mathematical calculations using scientific notation, dimensional analysis, and significant figures

Matter

DEFINITION OF MATTER

Matter is defined as anything that occupies space and has mass. Mass is the quantity of matter that a substance possesses and, depending on the gravitational force acting on it, has a unit of weight assigned to it. Although the weight can then vary, the mass of the body is a constant and can be measured by its resistance to a change of position or motion. This property of mass to resist a change of position or motion is called inertia. Since matter does occupy space, we can compare the masses of various substances that occupy a particular unit volume. This relationship of mass to a unit volume is called the density of the substance. It can be shown in a mathematical formula as D = m/V. A common unit of mass (m) in chemistry is the gram (g), and of volume (V) is the cubic centimeter (cm³) or milliliter (mL).

An example of how density varies can be shown by the difference in the volume occupied by 1 g of a metal, such as gold, and 1 g of styrofoam. Both have the same mass, that is, 1 g, but the volume occupied by the styrofoam is much larger. Therefore, the density of the metal will be much larger than that of the styrofoam. When dealing with gases in chemistry, the standard units for the density of gases are grams per liter at a standard temperature and pressure. This aspect of the density of gases is dealt with in Chapter 6. Basically then, density can be defined as the mass per unit volume.

STATES OF MATTER

Matter occurs in three states: solid, liquid, and gas. A solid has both a definite size and shape. A liquid has a definite volume but takes the shape of the container, and a gas has neither a definite shape nor a definite volume. These states of matter can often be changed by the addition of heat energy. An example of this is ice changing to liquid water and finally to steam.

COMPOSITION OF MATTER

Matter can be subdivided into two general categories: distinct (pure) substances and mixtures. Distinct substances are substances that can be subdivided into the smallest particle that still has the properties of the substance. At that point, if the substance is made up of only one kind of atom, it is called an element. Atoms are considered to be the basic building blocks of matter that cannot be easily created or destroyed. The word atom comes from the Greek and means the smallest possible piece of something. Today there are approximately 109 different kinds of atoms, each with its own unique composition. These atoms then are the building blocks of elements when only one kind of atom makes up the substance. If, however, there are two or more kinds of atoms joined together in definite grouping, this distinct substance is called a compound. Compounds are made by combining elements in a definite proportion (or ratio) by mass and are made up of two or more kinds of atoms. This is called the Law of Definite Composition (or Proportions). The smallest natural occurring unit of a compound is called a molecule of that compound. A molecule of a compound has a definite shape that is determined by how the atoms are bonded to or combine with each other. This bonding is described in Chapter 3. An example is the compound water: it always occurs in a two hydrogen atoms to one oxygen atom relationship. Mixtures, however, can vary in their composition.

In general, then:

Mixtures	Distinct Substances
	Elements
1.Composition is indefinite (generally heterogeneous).* (Example: marble) ...