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Bond. Chemical Bond.

Bond. Chemical Bond. ELECTRONEGATIVITY The tendency of an atom to attract electrons to itself when it is bonded to another atom. Check out Figure 5-20 on page 151. Where are electronegativities the greatest? The least?. OCTET. The eight outer electrons in an atom. FACT:

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Bond. Chemical Bond.

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  1. Bond.Chemical Bond.

  2. ELECTRONEGATIVITYThe tendency of an atom to attract electrons to itself when it is bonded to another atom

  3. Check out Figure 5-20 on page 151 • Where are electronegativities the greatest? • The least?

  4. OCTET The eight outer electrons in an atom

  5. FACT: Atoms with full outer energy levels are very stable (less reactive)

  6. OCTET RULE If an atom has 8 electrons in its outer energy level, it is unreactive (save He)

  7. Pretend we had a sub-energy level with 12 electrons. When would it be most stable?(The egg carton example)

  8. FACT #2: Atoms with filled, half filled, or empty sub-energy levels are slightly more stable

  9. Now…how do we make ENERGY LEVELS more stable?

  10. Ways to make full outer energy levels: • Add electrons to a partially filled outer energy level • Lose all electrons in the outer energy level • Share electrons with another atom

  11. Periodic Trends

  12. ATOMIC RADIUS The distance from the center of the nucleus to the outermost energy level

  13. The atomic radius INCREASES within a group (just adding energy levels)

  14. The atomic radius DECREASES within a period (more positive charge pulling e-)

  15. SHIELDING EFFECT The positive pull is less because the distance between nucleus and electrons is greater

  16. IONIZATION ENERGYthe energy required to remove an electron from an atom

  17. The ionization energy INCREASES across a period (more p+ have more pull on e-)

  18. The ionization energy DECREASES as you go down a group (shielding effect)

  19. ELECTRON AFFINITYhow much an atom desires another electron

  20. The electron affinity DECREASES as you go down a group (shielding effect)

  21. The electron affinity INCREASES across a period(except for the noble gases) (more p+ have more pull on e-)

  22. BOND STRENGTHthe energy needed to break the bonds between atoms in a compound

  23. Bond Strength The greater the difference in electronegativities, the greater the bond strength

  24. BONDING OPTIONS • By transferring electrons (producing ions) (big difference in EN) • By sharing electrons (small difference in EN)

  25. IONIC BONDbond formed between two ions by the transfer of electrons(difference in EN > 1.67)

  26. IONIC COMPOUNDsubstance formed when electrons are transferred between 2 or more substances(making ions)

  27. COVALENT BONDbond formed by the sharing of electrons(difference in EN < 1.67)

  28. MOLECULEa neutral group of atoms held together by covalent bonds(ex: H2O)

  29. WHICH IS STRONGER? Ionic bonds are stronger than covalent

  30. Bonds in all the polyatomic ions and diatomics are all covalent bonds

  31. IONIC BONDbond formed between two ions by the transfer of electrons

  32. IONIC COMPOUNDsubstance formed when electrons are transferred between 2 or more substances(making ions)

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