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Periodic Table

Periodic Table. The table is a remarkable way to show the relationships between different elements. The modern table was devised in 1869 by Dimitri Mendeleyev He arranged the elements by weight and by their chemical properties. Periods and Groups.

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Periodic Table

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  1. Periodic Table The table is a remarkable way to show the relationships between different elements. The modern table was devised in 1869 by Dimitri Mendeleyev He arranged the elements by weight and by their chemicalproperties

  2. Periods and Groups Horizontal rows in the periodic table are called periods Vertical columns are called groups We will learn later why the elements can be arranged in this fashion based on the arrangements of the electrons outside the nucleus

  3. Periods and Groups Valence Electrons in Group 2 Skippidy Do 3 4 5 6 7 8 -------- Too weird, so we skip them!------

  4. SIZE

  5. Horizontally Into Periods Elements are arranged: Vertically into Groups • All the elements in a column (GROUP) have remarkably similar chemical properties because they have the same number of VALENCE Electrons • Group 18 are the noble gasesand are basically inert or unreactive (full outer electron level) • All the elements in a Row (PERIOD) use the same number of Electron Levels.

  6. The group 2 atoms all have 2 electrons in their outer shells Be (Beryllium) Atom Mg (Magnesium) Atom

  7. http://www.lyon.edu/webdata/Users/DMcDowell/GenChem/alkalishow.htmlhttp://www.lyon.edu/webdata/Users/DMcDowell/GenChem/alkalishow.html Alkali Metals Soft, silvery colored metals Very reactive!!!

  8. Alkaline Earth Metals Silvery-White Metals Fairly reactive Many are found in rocks in the Earth’s crust

  9. Transition Metals Most are: Conductors of electricity and heat Malleable and Ductile (easily hammered into sheets or made into wires)

  10. Examples of things made from Transition Metals

  11. Nonmetals Brittle Do not conduct electricity

  12. Halogens Most are Poisonous Very reactive

  13. Noble Gases Unreactive Gases at room temperature

  14. Metals Lose valence electrons and form cations • Group 1 Elements lose 1 electron • Group 1 Elements become +1 cations • Group 2 Elements lose 2 electrons • Group 2 Elements become +2 cations

  15. Nonmetals Gain electrons and form anions • Group 17 Elements gain 1 electron • Group 17 Elements can form -1 anions • Group 16 Elements gain 2 electrons • Group 16 Elements can form -2 anions

  16. IPC Chemical Bonding IPC - Borders – 2012 update Hollocker 2013

  17. Bonds Between Atoms Ionic Covalent Metallic Molecular Substance

  18. Review of the following words before starting the lesson… • Anion- negative ion • Cation-positive ion • Octet Rule- rule that states that atoms tend to gain, lose, or share electrons so that each atom has full outermost energy level which is typically 8 electrons. • Molecule-neutral group of atoms united by covalent bonds

  19. Ionic Bonds • What is an Ionic Bond? • - An Ionic Bond is a chemical bond resulting from the TRANSFER of electrons from one bonding atom to another • When is an ionic bond formed? An ionic bond is formed when a Metal gives up one or more electrons to a Nonmetal

  20. Remember Lewis Dot Diagrams Na + Cl Na+1Cl-1 A Metal transfers electrons to a Nonmetal and becomes a cation(+ ion) The Nonmetal becomes an anion (-ion).

  21. Position indicates the bond Ionic Bond

  22. What are some characteristics of an ionic bond? • Crystalline at room temperatures • Have higher melting points and boiling points compared to covalent compounds • Conduct electrical current in molten or solution state but not in the solid state • Polar bonds

  23. Covalent Bonds • What is an Covalent Bond? • - A covalent bond is a chemical bond resulting from SHARING of electrons between 2 bonding atoms. • What forms a covalent bond? - A covalent bond is formed between two nonmetals.

  24. Remember Lewis Dot Diagrams An Example Two Nonmetals SHARE electrons to form a Compound. Octet Octet Octet OC O  CO2 Short form: O CO

  25. Position indicates the bond Covalent Bond (share close) Ionic Bond (give across)

  26. What are some characteristics of a covalent bond? • Covalent bonds have definite and predicable shapes. • Very strong • Low melting and boiling points

  27. Next, we are going to look at Molecular Substances… What is a molecular substance? -A molecular substance is a substance that has atoms held together by covalent bonds. Name 2 Characteristics of a Molecular Substance. • Weak • Low melting and boiling points

  28. Metallic Bonding Name 4 Characteristics of a Metallic Bond. What is a Metallic Bond? - A metallic bond occurs in metals. A metal consists of positive ions surrounded by a “sea” of mobile electrons. • Good conductors of heat and electricity • Great strength • Malleable and Ductile • Luster This shows what a metallic bond might look like.

  29. Metallic Bonding Electron Sea Model Occurs in Metals

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