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Unit 13 Lesson 6 What Is the Atomic Theory? Copyright © Houghton Mifflin Harcourt Publishing Company 2

Unit 13 Lesson 6 What Is the Atomic Theory? A Teeny Tiny Theory Substances can be broken down into increasingly smaller units. An atom is the smallest unit of an element that maintains the properties of that element. Atoms are the building blocks of all matter. Copyright © Houghton Mifflin Harcourt Publishing Company 3

Unit 13 Lesson 6 What Is the Atomic Theory? A Teeny Tiny Theory The atomic theory is a scientific explanation of the structure of atoms and how they interact with other atoms. Current atomic theory states that an atom is mostly empty space. At the center of an atom is a small, dense core called the nucleus, which is surrounded by electrons. Copyright © Houghton Mifflin Harcourt Publishing Company 4

Unit 13 Lesson 6 What Is the Atomic Theory? A Teeny Tiny Theory A proton is a positively charged particle found in the nucleus of an atom. Neutrons are particles found in the nucleus, but a neutron has no charge. Electrons are negatively charged particles that speed through an area around the nucleus called the electron cloud. Copyright © Houghton Mifflin Harcourt Publishing Company 5

A Teeny Tiny Theory Unit 13 Lesson 6 What Is the Atomic Theory? 6 Copyright © Houghton Mifflin Harcourt Publishing Company 6

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A Teeny Tiny Theory Unit 13 Lesson 6 What Is the Atomic Theory? 8 Copyright © Houghton Mifflin Harcourt Publishing Company 8

Putting It All Together Unit 13 Lesson 6 What Is the Atomic Theory? Putting It All Together How is a molecule formed? Many atoms go through chemical change with a different or same type of atom and form molecules. A molecule is made up of two or more atoms joined together chemically. Copyright © Houghton Mifflin Harcourt Publishing Company 9

Unit 13 Lesson 6 What Is the Atomic Theory? It’s Elementary! An element is a type of matter made of just one kind of atom. Elements are substances that cannot be broken into simpler substances. All atoms of an element have the same number of protons. For example, boron is an element. Every atom of boron contains exactly five protons. No other element has atoms with exactly five protons. Copyright © Houghton Mifflin Harcourt Publishing Company 10

Unit 13 Lesson 6 What Is the Atomic Theory? It’s Elementary! Electrons are far from the nucleus, so they can be gained or lost. Different atoms of the same element can contain different numbers of neutrons. Protons remain the same, at all times. Examples of elements include neon, mercury, chlorine, silver, and copper. Copyright © Houghton Mifflin Harcourt Publishing Company 11

It’s Elementary! Unit 13 Lesson 6 What Is the Atomic Theory? 12 Copyright © Houghton Mifflin Harcourt Publishing Company 12

It’s Elementary! Unit 13 Lesson 6 What Is the Atomic Theory? 13 Copyright © Houghton Mifflin Harcourt Publishing Company 13

It’s Elementary! Unit 13 Lesson 6 What Is the Atomic Theory? 14 Copyright © Houghton Mifflin Harcourt Publishing Company 14

Putting It All Together Unit 13 Lesson 6 What Is the Atomic Theory? Putting It All Together A compound is a substance formed by atoms from two or more elements. Copyright © Houghton Mifflin Harcourt Publishing Company 15

Putting It All Together Unit 13 Lesson 6 What Is the Atomic Theory? Putting It All Together The properties of a compound are often different from the properties of the elements that form it. For example, atoms of carbon and oxygen will react, forming the compound carbon dioxide. This compound has its own properties that are different than those of carbon or oxygen. Copyright © Houghton Mifflin Harcourt Publishing Company 16

Putting It All Together Unit 13 Lesson 6 What Is the Atomic Theory? Putting It All Together Copyright © Houghton Mifflin Harcourt Publishing Company 17

A Teeny Tiny Theory Unit 13 Lesson 6 What Is the Atomic Theory? 18 Copyright © Houghton Mifflin Harcourt Publishing Company 18

Putting It All Together Unit 13 Lesson 6 What Is the Atomic Theory? Putting It All Together Copyright © Houghton Mifflin Harcourt Publishing Company 19

Putting It All Together Unit 13 Lesson 6 What Is the Atomic Theory? Putting It All Together Copyright © Houghton Mifflin Harcourt Publishing Company 20

Unit 13 Lesson 6 What Is the Atomic Theory? Copyright © Houghton Mifflin Harcourt Publishing Company 21

Unit 13 Lesson 6 What Is the Atomic Theory? Copyright © Houghton Mifflin Harcourt Publishing Company 22

Unit 13 Lesson 6 What Is the Atomic Theory? Copyright © Houghton Mifflin Harcourt Publishing Company 23

Unit 13 Lesson 6 What Is the Atomic Theory? Copyright © Houghton Mifflin Harcourt Publishing Company 24

Unit 13 Lesson 6 What Is the Atomic Theory? Copyright © Houghton Mifflin Harcourt Publishing Company 25