1. © Copyright Pearson Prentice Hall Connecting to Your World Slide 1 of 52 Distinguishing Among Atoms Just as apples come in different varieties, a chemical element can come in different “varieties” called isotopes. CN#2

2. © Copyright Pearson Prentice Hall Distinguishing Among Atoms > Slide 2 of 52 4.3 Atomic Number What makes one element different from another?

3. © Copyright Pearson Prentice Hall Distinguishing Among Atoms > Slide 3 of 52 4.3 Atomic Number Elements are different because they contain different numbers of protons. The atomic number of an element is the number of protons in an atom. It is also the number of electrons.

4. © Copyright Pearson Prentice Hall Slide 4 of 52

5. © Copyright Pearson Prentice Hall Slide 5 of 52 Atomic Number

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7. © Copyright Pearson Prentice Hall Slide 7 of 52 Practice Problems for Conceptual Problem 4.1 Problem Solving 4.15 Solve Problem 15 with the help of an interactive guided tutorial.

8. © Copyright Pearson Prentice Hall Distinguishing Among Atoms > Slide 8 of 52 Mass Number How do you find the mass number of an atom? 4.3

9. Slide 9 of 52 © Copyright Pearson Prentice Hall > Distinguishing Among Atoms Mass Number The mass number is the total number of protons and neutrons in an atom. Mass number = protons + neutrons 4.3 Neutrons = mass number - protons

10. © Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 10 of 52 4.1

11. Slide 11 of 52 © Copyright Pearson Prentice Hall > Distinguishing Among Atoms Atomic Number 4.3

12. © Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 12 of 52 4.1

13. © Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 13 of 52 4.1

14. © Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 14 of 52 4.1

15. © Copyright Pearson Prentice Hall Slide 15 of 52 Practice Problems for Sample Problem 4.1 Problem Solving 4.17 Solve Problem 17 with the help of an interactive guided tutorial.

16. © Copyright Pearson Prentice Hall Distinguishing Among Atoms > Slide 16 of 52 Isotopes How do isotopes of an element differ? 4.3

17. Slide 17 of 52 © Copyright Pearson Prentice Hall > Distinguishing Among Atoms 4.3 Isotopes Isotopes are atoms that have the same number of protons but different numbers of neutrons. Because isotopes of an element have different numbers of neutrons, they also have different mass numbers.

18. Slide 18 of 52 © Copyright Pearson Prentice Hall > Distinguishing Among Atoms Isotopes Despite these differences, isotopes are chemically alike because they have identical numbers of protons and electrons. 4.3

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20. © Copyright Pearson Prentice Hall Slide 20 of 52

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22. © Copyright Pearson Prentice Hall Slide 22 of 52 Practice Problems for Conceptual Problem 4.2 Problem Solving 4.20 Solve Problem 20 with the help of an interactive guided tutorial.

23. © Copyright Pearson Prentice Hall Distinguishing Among Atoms > Slide 23 of 52 The Periodic Table—A Preview Why is a periodic table useful? 4.3

24. Slide 24 of 52 © Copyright Pearson Prentice Hall > Distinguishing Among Atoms The Periodic Table—A Preview A periodic table is an arrangement of elements in which the elements are separated into groups based on a set of repeating properties. A periodic table allows you to easily compare the properties of one element (or a group of elements) to another element (or group of elements). 4.3

25. Slide 25 of 52 © Copyright Pearson Prentice Hall > Distinguishing Among Atoms The Periodic Table—A Preview The Periodic Table 4.3

26. Slide 26 of 52 © Copyright Pearson Prentice Hall > Distinguishing Among Atoms The Periodic Table—A Preview Each horizontal row of the periodic table is called a period. Within a given period, the properties of the elements vary as you move across it from element to element. 4.3

27. Slide 27 of 52 © Copyright Pearson Prentice Hall > Distinguishing Among Atoms The Periodic Table—A Preview A Period 4.3

28. Slide 28 of 52 © Copyright Pearson Prentice Hall > Distinguishing Among Atoms The Periodic Table—A Preview Each vertical column of the periodic table is called a group, or family. Elements within a group have similar chemical and physical properties. 4.3

29. Slide 29 of 52 © Copyright Pearson Prentice Hall > Distinguishing Among Atoms The Periodic Table—A Preview A Group or Family 4.3

30. B Si Ge As SbTe AtPo H

31. © Copyright Pearson Prentice Hall Slide 31 of 52 Section Quiz -or- Continue to: Launch: Assess students’ understanding of the concepts in Section 4.3 Section Quiz 4.3.

32. © Copyright Pearson Prentice Hall Slide 32 of 52 4.3 Section Quiz 1. Isotopes of an element have a.the same mass number. b.different atomic numbers. c.the same number of protons but different numbers of neutrons. d.the same number of protons but different numbers of electrons.

33. © Copyright Pearson Prentice Hall Slide 33 of 52 4.3 Section Quiz 2. How many neutrons are in sulfur-33? a.16 neutrons b.33 neutrons c.17 neutrons d.32.06 neutrons

34. © Copyright Pearson Prentice Hall Slide 34 of 52 4.3 Section Quiz 3. If sulfur contained 90.0% sulfur-32 and 10.0% sulfur-34, its atomic mass would be a.32.2 amu. b.32.4 amu. c.33.0 amu. d.35.4 amu.

35. End Show © Copyright Pearson Prentice Hall Slide 35 of 52 Distinguishing Among Atoms > Concept Map

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