Download
chemical bonding and nomenclature n.
Skip this Video
Loading SlideShow in 5 Seconds..
Chemical Bonding and Nomenclature PowerPoint Presentation
Download Presentation
Chemical Bonding and Nomenclature

Chemical Bonding and Nomenclature

197 Vues Download Presentation
Télécharger la présentation

Chemical Bonding and Nomenclature

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Chemical Bonding and Nomenclature

  2. Atoms can form molecules bonds: • IONIC • COVALENT • METALLICGet to know the difference between IONIC and COVALENT BONDS based on what happens with the valence electrons.h LET’S FIRST REVIEW IONIC BONDING

  3. Opposites Attract! http://ed.ted.com/lessons/how-atoms-bond-george-zaidan-and-charles-morton

  4. K F In an IONIC bond, electrons are lost or gained, resulting in the formation of IONS in ionic compounds.

  5. K F

  6. K F

  7. K F

  8. _ + K F

  9. _ + K F The compound potassium fluoride consists of potassium (K+) ions and fluoride (F-) ions

  10. _ + K F The ionic bond is the attraction between the positive K+ ion and the negative F- ion

  11. _ + K F But….how do we know what ions are formed by different elements? Octet Rule: Atoms want full valence shells to be stable

  12. Forming Ions

  13. Forming Ions

  14. How do we know how many atoms of each in an ionic bond?You did this yesterdayIonic Compounds are stable – NEUTRAL Negative charge must equal the positive charge

  15. IONIC BONDS Look at the charge of each ion: Ca+2 & F -1 The charges do not balance – but they need to to get -2 charge to match Ca +2 charge we will need two F atoms

  16. IONIC FORMULAS To write a proper formula, you need to say how many atoms of each HOW DO YOU WRITE one Ca atom and two F atoms? CaF2 Subscripts: tells us number of atoms for each In example above, only 1 atom of Ca for the compound, so no subscript needed. F needs a subscript

  17. Putting Ions Together-Formulas Na+ + Cl- = NaCl Na+ + O-2 = Na2O Ca+2 + N-3 = Ca3N2 Al+3 + S-2 = Al2S3 You try these! Li+ + Br - = LiBr MgF2 Mg+2 + F - = KCl NH4+ + PO4-3 = (NH4)3PO4 K+ + Cl - =

  18. Ion Formulas Remember those polyatomic ions (poly-many atomic-atoms) They stay whole in compounds, need more than one, must do so for whole ion: Ca+2 & PO4-3cc: Written like this: Ca3(PO4)2

  19. Ion Formulas There is an easy short cut to figuring out the formulas….using the charges to figure out the subscripts… CRISS CROSS METHOD Ca+2 & F -1 criss-cross:

  20. Practice • Use Criss Cross Strategy • You will need periodic table

  21. IONIC BondingIonic Formula’s are RATIOS of Cations(+) to Anions(-) Sodium and Oxygen combine Na +1 Oxygen -2 Na2O (two Na atoms for every O atom every time!)

  22. Ionic Bonding ShortcutCriss Cross: use the charge of the positive charged element to determine the subscript for the opposite one Al +3 O -2 Al2 O3

  23. NomenclatureNaming of CompoundsFOR IONIC COMPOUNDS • Metal’s name goes first (cation)– do not change it except Iron = Ferrous • Non-metal (anion) name is changed • End of original name taken off and replaced with “ide” oxygen = oxide nitrogen= nitride flourine= flouride • REMEMBER Polyatomics stay as is, they keep their special names

  24. Naming Examples • Al2S3 Aluminum and Sulfur • Aluminum Sulfide Fe2O3 Ferrous (Iron) and Oxygen • Ferrous Oxide

  25. Let’s Practice! Name the following. CaF2 Calcium Flouride K2PO4 Potassium Phosphate SnF2 Tin (II) Flouride or Stannous Flouride SnF4 Tin (IV) Flouride or Stannic Flouride CuI2 Copper (II) Iodide or Cupric Iodide CuI Copper (I) Iodide or Cuprous Iodide SrS Strontium Sulfide Lithium Hydroxide LiOH

  26. The Covalent Bond Atoms can form molecules by sharing electrons. Covalent Bonding – bonding by sharing electrons This is done only among non-metal atoms.

  27. So what are covalent bonds?

  28. In covalent bonding, atoms still want to achieve a noble gas configuration (the octet rule).

  29. In covalent bonding, atoms still want to achieve a noble gas configuration (the octet rule). But rather than losing or gaining electrons, atoms now share an electron pair Called a Bonding Pair.

  30. Chlorine forms a covalent bond with itself Cl2

  31. How will two chlorine atoms react? Cl Cl

  32. Cl Cl Each chlorine atom wants to gain one electron to achieve an octet What’s the solution –what can they do to achieve an octet?

  33. Cl Cl

  34. Cl Cl

  35. Cl Cl octet

  36. Cl Cl octet circle the electrons for each atom that completes their octets

  37. Cl Cl The octet is achieved by each atom sharing the electron pair in the middle circle the electrons for each atom that completes their octets

  38. Cl Cl The octet is achieved by each atom sharing the electron pair in the middle circle the electrons for each atom that completes their octets

  39. Cl Cl This is the bonding pair It is called aSINGLE BOND circle the electrons for each atom that completes their octets

  40. Cl Cl Single bonds are abbreviated with a dash Write this as an example of a single covalent bond circle the electrons for each atom that completes their octets

  41. Cl Cl This is the chlorine molecule, Cl2 circle the electrons for each atom that completes their octets

  42. O2 Oxygen is also one of the diatomic molecules

  43. O O How will two oxygen atoms bond?

  44. O O Each atom has two unpaired electrons

  45. O O

  46. O O

  47. O O

  48. O O

  49. O O Both electron pairs are shared.

  50. O O 6 valence electrons plus 2 shared electrons = full octet