1. Warm-Up: Write vocab. & objectives in your notes for today. Vocab.: -element, -matter, -atom, - electrons, -protons, -neutrons, -atomic number, -atomic mass, -isotope. Objectives: 1. Identify & determine the subatomic particles of an element. 2. Determine the atomic number of an element. 3. Calculate the atomic mass of an element. 1

2. LecturePLUS Timberlake2 Atoms & Elements The Atom Atomic Number Mass Number Isotopes

3. LecturePLUS Timberlake3 Atoms: The Stuff of Life Matter: any substance that has mass & occupies space. All matter is composed of very small particles called atoms. Niels Bohr- Danish physicist proposed that atoms contain a cloud of electrons orbiting it.

4. Atoms (continued) Every atom has subatomic particles called electrons (- charge) surrounding it like a mini solar system. The atoms nucleus is made of 2 other kinds of subatomic particles, protons (+ charge) & neutrons (no charge). Usually, # electrons = # protons (atomic number) 4

5. LecturePLUS Timberlake5 Subatomic Particles ParticleSymbol Charge Relative Mass Electron e - 1- 0 Proton p + + 1 Neutron n0 1

6. LecturePLUS Timberlake6 Location of Subatomic Particles 10 -13 cm electrons protons neutrons 10 -8 cm nucleus

7. LecturePLUS Timberlake7 Atomic Number Is equal to the number of protons in an atom.

8. LecturePLUS Timberlake8 Atomic Number on the Periodic Table 11 Na Atomic Number Symbol

9. LecturePLUS Timberlake9 All atoms of an element have the same number of protons as the atomic number 11 Na 11 protons Sodium

10. LecturePLUS Timberlake10 Learning Check #1; Use your periodic table to answer the following into your notes: 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

11. LecturePLUS Timberlake11 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

12. LecturePLUS Timberlake12 Atomic Mass In an atom, counts the number of Protons + neutrons = Atomic mass So, to calculate neutrons: neutrons = atomic mass - protons

13. 13 Atomic Symbols Show the atomic mass and atomic number Give the symbol of the element Element = substance that cannot be broken down by ordinary chemical means. Atomic Mass 23 Na sodium-23 atomic Number 11 (# protons)

14. LecturePLUS Timberlake14 Subatomic Particles in Some Atoms 16 31 65 O P Zn 8 15 30 8 p + 15 p + 30 p + 8 n16 n35 n 8 e - 15 e - 30 e -

15. LecturePLUS Timberlake15 Isotopes Atoms with the same number of protons, but different numbers of neutrons. Atoms of the same element (same atomic number) with different atomic masses. Isotopes of chlorine 35 Cl 37 Cl17 chlorine - 35 chlorine - 37

16. LecturePLUS Timberlake16 Learning Check #2 Naturally occurring carbon consists of three isotopes, 12 C, 13 C, and 14 C. State the number of protons, neutrons, and electrons in each of these carbon atoms. 12 C 13 C 14 C 6 6 6 #p _______ _______ _______ #n _______ _______ _______ #e _______ _______ _______

17. LecturePLUS Timberlake17 Solution 12 C 13 C 14 C 6 6 6 #p 6 6 6 #n 6 7 8 #e 6 6 6

18. LecturePLUS Timberlake18 Learning Check #3 An atom of zinc has an atomic mass of 65. A.Number of protons in the zinc atom 1) 302) 353) 65 B.Number of neutrons in the zinc atom 1) 302) 353) 65 C. What is the atomic mass of a zinc isotope with 37 neutrons? 1) 372) 653) 67

19. LecturePLUS Timberlake19 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 atomic mass of a zinc isotope with 37 neutrons? 3) 67

20. LecturePLUS Timberlake20 Learning Check #4 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 - ___________

21. LecturePLUS Timberlake21 Solution 16 O A. 8 p +, 8 n, 8 e - 8 B.17p +, 20n, 17e - 37 Cl 17 C. 47p +, 60 n, 47 e - 107 Ag 47

22. LecturePLUS Timberlake22 Atomic Mass on the Periodic Table 11 Na 22.99 Atomic Number Symbol Atomic Mass