1. You should view this in slideshow mode and make sure to enable active content if asked Copyright © Houghton Mifflin Company. All rights reserved.2–12–1

2. Chapter Two: ATOMS, MOLECULES, AND IONS

3. Fundamental Chemical Laws

4. Copyright © Houghton Mifflin Company. All rights reserved.2–42–4 Three Important Laws Law of conservation of mass –Mass is neither created nor destroyed Law of definite proportion –A given compound always contains exactly the same proportion of elements by mass

5. Copyright © Houghton Mifflin Company. All rights reserved.2–52–5 Three Important Laws (continued) Law of multiple proportions –When two elements form a series of compounds, the ratios of the masses of the second element that combine with 1 gram of the first element can always be reduced to small whole numbers. –Why do you think this is?

6. Dalton’s Atomic Theory

7. Copyright © Houghton Mifflin Company. All rights reserved.2–72–7 Dalton’s Atomic Theory (1808) Each element is made up of tiny particles called atoms.

8. Copyright © Houghton Mifflin Company. All rights reserved.2–82–8 Dalton’s Atomic Theory (1808) (continued) The atoms of a given element are identical; the atoms of different elements are different in some fundamental way or ways.

9. Copyright © Houghton Mifflin Company. All rights reserved.2–92–9 Dalton’s Atomic Theory (continued) Chemical compounds are formed when atoms combine with each other. A given compound always has the same relative numbers and types of atoms.

10. Copyright © Houghton Mifflin Company. All rights reserved.2–10 Dalton’s Atomic Theory (continued) Chemical reactions involve reorganization of the atoms - changes in the way they are bound together. The atoms themselves are not changed in a chemical reaction.

11. Copyright © Houghton Mifflin Company. All rights reserved.2–11 Avogadro’s Hypothesis (1811) At the same temperature and pressure, equal volumes of different gases contain the same number of particles. –5 liters of oxygen –5 liters of nitrogen –Same number of particles!

12. Copyright © Houghton Mifflin Company. All rights reserved.2–12 Representing Gay-Lussac’s Results

13. Copyright © Houghton Mifflin Company. All rights reserved.2–13 Representing Gay-Lussac’s Results

14. The Modern View of Atomic Structure: An Introduction

15. Copyright © Houghton Mifflin Company. All rights reserved.2–15 The Modern View of Atomic Structure The atom contains: –electrons –protons: found in the nucleus; positive charge equal in magnitude to the electron’s negative charge. –neutrons: found in the nucleus; no charge; virtually same mass as a proton.

16. Copyright © Houghton Mifflin Company. All rights reserved.2–16 Nuclear Atom Viewed in Cross Section

17. Copyright © Houghton Mifflin Company. All rights reserved.2–17 Isotopes Isotope—two atoms of the same element with different numbers of neutrons –Different masses –Unstable isotopes are radioactive Written as:

18. Copyright © Houghton Mifflin Company. All rights reserved.2–18 Two Isotopes of Sodium

19. Molecules and Ions

20. Copyright © Houghton Mifflin Company. All rights reserved.2–20 Ionic and Covalent Bonds Covalent Bond—a bond which forms as a result of sharing electrons Ionic Bond—a bond which forms as a result of an attraction between oppositely charged ions –Ions receive charges by gaining or losing electrons Cation Anion

21. Copyright © Houghton Mifflin Company. All rights reserved.2–21 Molecular vs. Ionic Compounds

22. Copyright © Houghton Mifflin Company. All rights reserved.2–22 Covalent Bonding

23. Copyright © Houghton Mifflin Company. All rights reserved.2–23 Formation of Ionic Compounds

24. An Introduction to the Periodic Table

25. Copyright © Houghton Mifflin Company. All rights reserved.2–25 The Periodic Table

26. Naming Simple Compounds

27. Copyright © Houghton Mifflin Company. All rights reserved.2–27 Flowchart for Naming Binary Compounds Always end with -ide Never use mono- on the 1 st element

28. Copyright © Houghton Mifflin Company. All rights reserved.2–28 Overall Strategy for Naming Chemical Compounds Polyatomic ions do not end with -ide

29. Copyright © Houghton Mifflin Company. All rights reserved.2–29 Table 2.5 Common Polyatomic Ions

30. Copyright © Houghton Mifflin Company. All rights reserved.2–30 Flowchart for Naming Acids