The Periodic Table of Elements

Ch. 16 Periodic Table Dmitri Mendeleev published the 1st Periodic 1869 - – His periodic table was organized according to , and a he noticed a pattern resulted where elements aligned in groups had similar properties – He reorganized the periodic table by placing the elements in – states that chemical properties of elements are based on and Atomic weight Henry Moseley reorganized the Periodic Table order of Increasing Atomic Number Periodic Law Groups Atomic Number. 1. History of the Periodic table and Atomic Models (Pg. 2)

2. History of Atomic Models 400 B.C. Democritus 1904 Thomson 1911 Rutherford 1926 Electron Cloud Bohr Model: energy levels surround the nucleus with electrons. Each level can hold a max. amount of electrons (2, 8, 18, 32)   Electron Cloud: the electron cloud surrounds the nucleus. The cloud is where electrons are most likely to be found. Each energy level has orbitals s,p,d,f. 1913 Bohr Level 1 – s Level 2 – s,p Level 3 – s,p,d Level 4 – s,p,d,f

1+ Metals Most Reactive – Fr francium Most Metallic- Group 1 Least Metallic- Metals in Groups 13 – 16 Common Properties of metals – good conductors, Hard, shiny, malleable, ductile, solid, give electrons Common Properties of semiconductors/metalloids – Poor conductors, shiny & dull, properties of both metals and nonmetals 2+ 3+ 4+- 3- 2- 1- F * * Br * * * * * * Hg Nonmetals Most Reactive- F, Fluorine Inert Nonmetals (nonreactive)- Group 18, Noble Gases Common Properties of nonmetals - poor conductors, brittle, dull, take electrons Liquids at Room Temperature – Hg, Br Fr Groups: 1 – 18, # of valence electrons, elements in groups have similar properties Periods: 1 – 7, # of energy levels around the nucleus

4. How to Solve for the Atomic #,Mass, Protons, & Electrons Subatomic Particles: Negative charge, surround the nucleus in the electron cloud. When bonds are formed (compounds) electrons will be given, taken or shared   Positive charge, found inside the nucleus, the # of protons is unique for each element no charge, found in the nucleus An arrangement of 3 produce a proton; Another arrangement produces a neutron = # of Protons & # of Electrons = Atomic Mass – Atomic # (or # P or #e-) = Atomic # (or # P or # e-) + Neutrons Atoms of the same element, (ex. Carbon) that have different #’s of neutrons are . Protons, Neutrons, Electrons, Quarks ELECTRONS: PROTONS: NEUTRONS:     QUARKS: Atomic # # Neutrons Atomic Mass Isotopes

Isotopes Atoms of the same element ( same # of protons), but different numbers of neutrons.       Notice that each of these atoms have one proton; therefore they are all types of hydrogen.  They just have a different mass number (# of neutrons).

Isotopes analogy is like having different versions of the same Lexus

Complete the element chart below Atomic # Atomic Mass Protons Neutrons Electrons C   12 Oxygen 8 24 19 9 Ne 10 Beryllium 4 5 5. Atomic #, Mass, Protons & Electrons

6. How to Draw a Bohr Model Steps for Bohr model 1. Find element on the periodic table. 2. List the atomic #, atomic mass, # of protons, electrons and neutrons. 3. Draw a circle representing the nucleus and write inside of it the # of protons and neutrons. 4. Write down what period your element is in. This will tell you how many energy levels/rings you will draw around your nucleus. 5. Draw your energy levels around your nucleus. 6. Fill your first energy level closest to the nucleus with dots representing two electrons. 7. Look on the periodic chart to see how many valence electrons your element has, roman numeral #. 8. Fill your last energy level with the # of valence electrons your element should have. 9. Add up the total amount of electrons you have on the first and last energy level. Subtract this number from the total # of electrons and this will tell you how many you should have on your 2nd energy level. Now count up all the electrons you put on your energy levels and it should be the same # you wrote down to start with. 10. Draw your Lewis dot diagram, element symbol with the valence electrons around the symbol. 11. Total number of electrons you can have on each energy level – 1st-2, 2nd – 8, 3rd – 18, 4th - 32

7. Bohr Model Hydrogen Atomic #: Atomic mass: # Protons: # Neutrons:   Atomic #: Atomic mass: # Protons: # Neutrons: # Electrons: Period: # Valence Electrons Fluorine Carbon Aluminum 7. Bohr Model