Atoms and Atomic Structure

1. Atoms and Atomic Structure Protons, Neutrons, Electrons Atomic/Bohr Models

2. The Atom • 3 parts • 1. Protons = positive charge • 2. Neutrons = neutral charge • 3. Electrons = negative charge Nucleus = Protons + Neutrons

3. Elements • A pure substance that cannot be broken down into other substances Water Gold • Hydrogen • Oxygen • Gold

4. Protons, Neutrons, Electrons • All atoms we draw will have equal protons and electrons Atomic Number 1 Atomic Symbol H 1.0 Atomic Mass

5. Protons, Neutrons, Electrons • # of protons = look at the atomic number • # of electrons = look at the atomic number • # of neutrons = subtract the atomic number from the atomic mass Atomic Number 1 Atomic Symbol H 1.0 Atomic Mass

6. Practice P = P = 2 21 N = N = He Sc E = E = 4.0 45.0 P = P = 11 19 N = N = H K E = E = 23.0 39.0

7. Periodic Table Parts • Periods: move from left to right across the periodic table (7 periods) • Groups: move from top to bottom down the periodic table (18 groups)

8. The Periodic Table

9. Group 1 Metals • Alkali Metals Lithium Very Reactive Sodium 1Electron in outer level Potassium Rubidium Cesium Francium

10. Group 2 • Alkaline-Earth Metals Metals Beryllium Reactive, but not as reactive as Alkali Metals Magnesium Calcium Strontium 2Electrons in outer level Barium Radium

11. Groups 3-12 1or 2Electrons in outer level • Transition Metals

12. Lanthanides and Actinides Lanthanides Actinides

13. Groups 13-16 w/ Metalloids • Boron Group 13 Reactive Solid at Room Temperature 3Electrons in outer level

14. Groups 13-16 w/ Metalloids • Carbon Group 14 Reactivity varies among the elements Solid at room temperature 4Electrons in outer level

15. Groups 13-16 w/ Metalloids • Nitrogen Group 15 Reactivity varies among elements All but nitrogen are solid at room temp 5Electrons in outer level

16. Group 13-16 w/ Metalloids • Oxygen Group 16 Reactive All but oxygen are solid at room temp 6Electrons in outer level

17. Group 17 • Halogens Very Reactive React violently with alkali metals to form salts 7 Electrons in outer level

18. Group 18 • Noble Gases Unreactive Colorless, odorless gases at room temp 8Electrons in outer level (2 for Helium)

19. What About Hydrogen? • Hydrogen stands alone Reactive Colorless, odorless gas at room temp Explosive reaction with oxygen

20. Groups are arranged due to all members top to bottom having similar Physical and Chemical properties.