1. © Copyright Pearson Prentice Hall Distinguishing Among Atoms > Slide 1 of 52 4.3 Atomic Number Elements are _____________ because they contain ___________ ___________ of ______________. The ____________ ______________ of an element is the ____________ of ________________ in the __________ of an atom of that element.

2. Slide 2 of 52 © Copyright Pearson Prentice Hall > Distinguishing Among Atoms Atomic Number 4.3

3. © Copyright Pearson Prentice Hall Slide 3 of 52

4. © Copyright Pearson Prentice Hall Slide 4 of 52 Practice Problems for Conceptual Problem 4.1 Problem Solving 4.15 Solve Problem 15 with the help of an interactive guided tutorial.

5. Slide 5 of 52 © Copyright Pearson Prentice Hall > Distinguishing Among Atoms Mass Number The total number of _________ and ________ in an atom is called the ________ __________. The number of _______________ in an atom is the ____________ between the _________ number and ____________ number. 4.3

6. © Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 6 of 52 4.1

7. © Copyright Pearson Prentice Hall Slide 7 of 52 End Show for Sample Problem 4.1

8. Slide 8 of 52 © Copyright Pearson Prentice Hall > Distinguishing Among Atoms 4.3 Isotopes _____________ are atoms that have the same number of _______________ but different numbers of ______________. Because isotopes of an element have different ________ of __________, they also have different _______ _______________.

9. Slide 9 of 52 © Copyright Pearson Prentice Hall > Distinguishing Among Atoms Isotopes Despite these differences, isotopes are _____________ _______________ because they have identical numbers of ___________ and _______________________. 4.3

10. © Copyright Pearson Prentice Hall Slide 10 of 52

11. © Copyright Pearson Prentice Hall Slide 11 of 52 End Show for Conceptual Problem 4.2

12. Slide 12 of 52 © Copyright Pearson Prentice Hall > Distinguishing Among Atoms Atomic Mass It is useful to to compare the relative masses of atoms to a standard reference isotope. Carbon- 12 is the standard reference isotope. Cabon-12 has a mass of exactly 12 atomic mass units. An __________ _____________ __________ (amu) is defined as one twelfth of the mass of a ___________-____ atom. 4.3

13. Slide 13 of 52 © Copyright Pearson Prentice Hall > Distinguishing Among Atoms Atomic Mass The ________ ________________ of an element is a ___________ ________ ___________ of the atoms in a naturally occurring sample of the element. A weighted average mass reflects both the ___________ and the ___________ _____________ of the isotopes as they occur in nature. 4.3

14. Slide 14 of 52 © Copyright Pearson Prentice Hall > Distinguishing Among Atoms Atomic Mass Weighted Average Mass of a Chlorine Atom 4.3

15. © Copyright Pearson Prentice Hall Slide 15 of 52

16. © Copyright Pearson Prentice Hall Slide 16 of 52 End Show for Conceptual Problem 4.3

17. © Copyright Pearson Prentice Hall Distinguishing Among Atoms > Slide 17 of 52 Atomic Mass To calculate the atomic mass of an element, multiply the ___________ of each isotope by its _________ ______________, expressed as a decimal, and then _________ the products. 4.3

18. © Copyright Pearson Prentice Hall SAMPLE PROBLEM Slide 18 of 52 4.2

19. © Copyright Pearson Prentice Hall Slide 19 of 52 Practice Problems for Sample Problem 4.2 Problem Solving 4.24 Solve Problem 24 with the help of an interactive guided tutorial.

20. Slide 20 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

21. Slide 21 of 52 © Copyright Pearson Prentice Hall > Distinguishing Among Atoms The Periodic Table—A Preview Each ____________ row of the periodic table is called a ____________. Within a given period, the ___________ of the elements __________ as you move ___________ it from element to element. 4.3

22. Slide 22 of 52 © Copyright Pearson Prentice Hall > Distinguishing Among Atoms The Periodic Table—A Preview A Period 4.3

23. Slide 23 of 52 © Copyright Pearson Prentice Hall > Distinguishing Among Atoms The Periodic Table—A Preview Each ____________ column of the periodic table is called a _____________, or family. Elements within a ______________ have ____________ chemical and physical properties. 4.3

24. Slide 24 of 52 © Copyright Pearson Prentice Hall > Distinguishing Among Atoms The Periodic Table—A Preview A Group or Family 4.3