The Periodic Table

1. The Periodic Table A Well Ordered Thing

2. History Creator – Dmitri Mendeleev • Arranged elements in order of increasing atomic masses • Noticed that these elements showed similarities in their chemical properties with regular intervals • Came up with the PERIODIC LAW – The physical and chemical properties of the elements are periodic functions of their atomic numbers • Left empty spaces in periodic table for elements yet to be discovered

3. Robert Mosley – creator of modern periodic table - analyzed Mendeleev’s periodic table 1911 - Arranged elements in increasing order according to nuclear charge - His discovery led to the recognition of atomic number as the basis for the organization of periodic table

4. Categories METALS Make up more than 75% of the elements found in the periodic table Located on the left hand side of periodic table They have metallic shine or luster Good conductors of electricity Almost all are solids Malleable (hammered into sheets) Ductile (can be drawn into wires) Outer levels contain few electrons Form cations (lose electrons) Low ionization energies Low electron negativities

5. NONMETALS There are 17 nonmetals found on the periodic table Located on the right hand side of the periodic table Lack metallic shine or luster Poor conductors of electricity Can be solids, liquids or gases Non-malleable (Brittle) Non-ductile Outer level contains 4 or more electrons Form anions (gain electrons) High ionization energies High electron negativities

6. METALLIODS There are 8 metalloids found on the periodic table Boron, Silicon, Germanium, Arsenic, Antimony, Tellurium, Polonium and Astatine They are also known as semiconductors They are the dividing line between metals and nonmetals They contain properties similar to metals and nonmetals

7. The Periodic Table On the periodic table You will find the symbol, name, atomic number, and atomic weight for each element. For this class all atomic weights will be classified in whole numbers

8. Groups • These are the vertical columns • They are also known as “Families” • There are eighteen groups • Elements in a Family have the same number of valence electrons (electrons found in the outer most energy level) • Elements in a Family share similar physical and chemical properties

9. Some Families have specific names and some have common names such as: • Group 1 Alkali Metals • Group 2 Alkaline Earth Metals • Groups 3-12 Transition Metals • Group 13 Boron Family • Group14 Carbon Family • Group 15 Nitrogen Family • Group 16 Oxygen Family • Group17 Halogens • Group 18 Noble Gases

10. Periods • These are the horizontal columns • They are also known as “Shells” or “Energy Levels” • There are 7 Periods (7 energy levels) • Each Period has a distinct letter name • Elements in a Period increase in atomic number by 1 electron • Elements in a Period do not have similar physical and chemical properties • As you travel across a Period you are going from metals to nonmetals

11. The Periodic Table • A map of the building block of matter. http://www.chemsoc.org/viselements/pages/periodic_table.html

12. Halogen Alkali NobleGas Alkaline (earth) Chalcogens Transition Metals

13. Energy Levels and Electrons

14. Color Code and label your Periodic Table as Shown. Use the Roman Numerals when labeling families

15. Uses of the Periodic Table There are many uses of the periodic table but we will concerned with the electrons- 1) how many there are 2) where they are located 3) how they react with other electrons in chemical bonds

16. Electron Arrangement Location You can determine how an atom’s electrons are arranged if you know where the corresponding element is located on the periodic table

17. For Instance Hydrogen is found in the first period. It’s atomic number is 1 so it has 1 electron k 1H1 1e_) 1 This tells me the symbol for Hydrogen, its atomic number and mass, that it is found in the first period which is labeled k and that there is 1 electron found in the first energy level.

18. Boron is found in the second period. It’s atomic number is 5 so it has 5 electrons k l 5B11 2e-) 3e- ) 1 2 Once again, this tells me the symbol for Boron, its atomic number and mass, that it has electrons in the first and second period which are labeled k and l and that there are 2 electrons in the first period and 3 electrons in the second period

19. Detailing the energy levels Another way that you can show electron arrangement is by adding the orbitals found in the energy levels. For this you must follow the rules for orbital notation Hund’s Rule (Diagonal Rule) is based on the Aufbau Principle Electrons will occupy the lowest energy orbital that can receive it and if there are more than one orbital in the same energy level then each orbital must be occupied by one electron before any orbital can occupy a second electrons ** Remember each orbital can hold 2 electrons

20. Orbitals

21. Orbtial and Electron Capacity SUBLEVEL# of ORBTIALMAXIMUM e- s 1 2 p 3 6 d 5 10 f 7 14

22. Hund’s Rule: The Order of Filling Orbitals RUL:ES: To place electrons in their correct energy level and orbitals use the TAIL HEAD method. Follow the tail of the arrow to the head of the arrow

23. Let’s go back to Hydrogen k 1H1 1e- s)) 1 And Boron k l 5B11 2e- s)) 2e- s) 1e- p)) 1 2

24. Electron Configuration Hydrogen 1H11s1 Boron 5B11 1s2 2s2 2p1

25. Spin Notation You can also show how the electrons “behave” in the orbital Hydrogen 1H1  1s Do you see a pattern? Boron 5B11  __ __ 1s 2s 2p