Elements

1. Elements

2. Periodic Table • The periodic table organizes the Elements • Understanding the periodic table will help you learn about each of the 118 known elements.

3. Key to the Periodic Table • Element square • Identifies each known element • Symbol • Name • Atomic Number • Mass Number

4. Atomic Number • This refers to how many protons an atom of that element has. • No two elements, have the same number of protons. Bohr Model of Hydrogen Atom Wave Model

5. Learning Check State the number of protons for atoms of each of the following: A. Nitrogen 1) 5 protons 2) 7 protons 3) 14 protons B. Sulfur 1) 32 protons 2) 16 protons 3) 6 protons C. Barium 1) 137 protons 2) 81 protons 3) 56 protons LecturePLUS Timberlake

6. Solution State the number of protons for atoms of each of the following: A. Nitrogen 2) 7 protons B. Sulfur 2) 16 protons C. Barium 3) 56 protons LecturePLUS Timberlake

7. Atomic Mass • Atomic Mass refers to the “weight” of the atom. • Add the number of protons with the number of neutrons. This is a helium atom. Its atomic mass is 4 (protons plus neutrons). What is its atomic number? H

8. Number of Neutrons • Mass Number – Atomic Number • Or • Protons + Neutrons • - Protons • Number of Neutrons • Because it’s and average • Round the number

9. Virtual School Atomic and Mass Number • http://www.youtube.com/watch?v=_S7ov25y3_M&feature=edu&list=PL64B4E713AC151B87&edufilter=s_UX_rN7asYugcCwXdZRJg

10. Learning Check • How Many Neutrons in • 1. Cr Mass Number = 51.996 • 2. Fr Mass Number = 223 • 3. Mg Mass Numb er = 24.305 • 4. Si Mass Number = 28.086

11. Learning Check • How Many Neutrons in • 1. Cr Mass Number = 51.996 27.996 • 2. Fr Mass Number = 223 • 136 • 3. Mg Mass Number = 24.305 • 12.305 • 4. Si Mass Number = 28.086 • 14.086

12. Number of Electrons • Number of protons = Number of electrons • Atomic number = Number of electrons LecturePLUS Timberlake

13. Learning Check • How many electrons are in • 1. K • 2. Ca • 3. Ba • 4. O • 5. Br

14. Learning Check • How many electrons are in • 1. K • 19 • 2. Ca • 20 • 3. Ba • 56 • 4. O 8 • 5. Br • 35

15. Isotopes • Atoms with the same number of protons, but different numbers of neutrons. Isotopes of chlorine 35Cl 37Cl 1717 chlorine - 35 chlorine - 37 LecturePLUS Timberlake

16. Virtual School Isotopes • http://www.youtube.com/watch?v=xjY5p-1CDr8&feature=edu&list=PL64B4E713AC151B87&edufilter=s_UX_rN7asYugcCwXdZRJg

17. Virtual School Example of Isotopes • http://www.youtube.com/watch?v=9d3NcxFG3RQ&feature=edu&list=PL64B4E713AC151B87&edufilter=s_UX_rN7asYugcCwXdZRJg

18. Learning Check Naturally occurring carbon consists of three isotopes, 12C, 13C, and 14C. State the number of protons, neutrons, and electrons in each of these carbon atoms. 12C 13C 14C 6 6 6 #p _______ _______ _______ #n _______ _______ _______ #e _______ _______ _______ LecturePLUS Timberlake

19. Solution 12C 13C 14C 6 6 6 #p 6 6 6 #n 6 7 8 #e 6 6 6 LecturePLUS Timberlake

20. Learning Check An atom of zinc has a mass number of 65. A. Number of protons in the zinc atom 1) 30 2) 35 3) 65 B. Number of neutrons in the zinc atom 1) 30 2) 35 3) 65 C. What is the mass number of a zinc isotope with 37 neutrons? 1) 37 2) 65 3) 67 LecturePLUS Timberlake

21. Solution An atom of zinc has a mass number of 65. A. Number of protons in the zinc atom 1) 30 B. Number of neutrons in the zinc atom 2) 35 C. What is the mass number of a zinc isotope with 37 neutrons? 3) 67 LecturePLUS Timberlake

22. Learning Check Write the atomic symbols for atoms with the following: A. 8 p+, 8 n, 8 e- ___________ B. 17p+, 20n, 17e- ___________ C. 47p+, 60 n, 47 e- ___________ LecturePLUS Timberlake

23. Solution 16O A. 8 p+, 8 n, 8 e- 8 B. 17p+, 20n, 17e- 37Cl 17 C. 47p+, 60 n, 47 e- 107Ag 47 LecturePLUS Timberlake