1 / 63

I’m Bond, Chemical Bond

I’m Bond, Chemical Bond. Atom – the smallest unit of matter “indivisible”. Helium atom. electron shells. Atomic number = number of Electrons Electrons vary in the amount of energy they possess, and they occur at certain energy levels or electron shells.

tsandy
Télécharger la présentation

I’m Bond, Chemical Bond

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. I’m Bond, Chemical Bond

  2. Atom – the smallest unit of matter “indivisible” Helium atom

  3. electron shells • Atomic number = number of Electrons • Electrons vary in the amount of energy they possess, and they occur at certain energy levels or electron shells.

  4. Electrons are placed in shells according to rules: • The 1st shell can hold up to two electrons, and each shell thereafter can hold up to 8 electrons.

  5. Octet Rule = atoms tend to gain, lose or share electrons so as to have 8 electrons Gain 4 electrons • C would like to • N would like to • O would like to Gain 3 electrons Gain 2 electrons

  6. Why are electrons important? • Elements have different electron configurations • different electron configurations mean different ways of bonding – and different products from their reactions

  7. Noble gases

  8. Electron Dot Structures Symbols of atoms with dots to represent the outermost shell electrons 1 2 3 4 5 6 7 2/8 H He:      LiBe B  C  N  O : F :Ne :            Na Mg AlSiPS:Cl  :Ar :    

  9. Chemical bonds: an attempt to fill electron shells • Ionic bonds – • Covalent bonds – • Metallic bonds

  10. Learning Check  A. X would be the electron dot formula for 1) Na 2) K 3) Al   B.  X  would be the electron dot formula  1) B 2) N 3) P

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

  12. Formation of Ions from Metals • Ionic compounds result when metals react with nonmetals • Metals loseelectrons to match the number of outermost shell electrons of their nearest noble gas • Positive ionsform when the number of electrons are less than the number of protons Group 1 metals ion 1+ Group 2 metals ion 2+ • Group 13 metals ion 3+

  13. Formation of Sodium Ion Sodium atom Sodium ion Na  – e Na + 2-8-1 2-8 ( = Ne) 11 p+ 11 p+ 11 e- 10 e- 01+

  14. Formation of Magnesium Ion Magnesium atom Magnesium ion  Mg  – 2e Mg2+ 2-8-2 2-8 (=Ne) 12 p+ 12 p+ 12 e- 10 e- 0 2+

  15. Some Typical Ions with Positive Charges (Cations) Group 1 Group 2 Group 13 H+ Mg2+ Al3+ Li+ Ca2+ Na+ K+

  16. Learning Check A. Number of outermost shell electrons in aluminium 1) 1 e- 2) 2 e- 3) 3 e- B. Change in electrons for octet 1) lose 3e- 2) gain 3 e- 3) gain 5 e- C. Ionic charge of aluminium 1) 3- 2) 5- 3) 3+

  17. Solution A. Number of outermost shell electrons in aluminium 3) 3 e- B. Change in electrons for octet 1) lose 3e- C. Ionic charge of aluminium 3) 3+

  18. Learning Check Give the ionic charge for each of the following: A. 12 p+ and 10 e- 1) 0 2) 2+ 3) 2- B. 50p+ and 46 e- 1) 2+ 2) 4+ 3) 4- C. 15 p+ and 18e- 2) 3+ 2) 3- 3) 5-

  19. Ions from Nonmetal Ions • In ionic compounds, nonmetals gain electrons from metals • Nonmetal add electrons to achieve the octet arrangement • Nonmetal ionic charge: 3-, 2-, or 1-

  20. Fluoride Ion unpaired electron octet 1 - : F  + e: F :  2-7 2-8 (= Ne) 9 p+ 9 p+ 9 e- 10 e- 0 1 - ionic charge

  21. Ionic Bond • Between atoms of metals and nonmetals • Bond formed by transferof electrons • Produce charged ions. Conductors and have high melting point. • Examples; NaCl, CaCl2, K2O

  22. 1). Ionic bond – electron from Na is transferred to Cl, this causes a charge imbalance in each atom. The Na becomes (Na+) and the Cl becomes (Cl-), charged particles or ions.

  23. http://www.youtube.com/watch?v=Ftw7a5ccubs

  24. COVALENT BONDbond formed by the sharing of electrons

  25. Covalent Bond • Between nonmetallic elements • Formed by sharing electron pairs • Stable non-charged particles, they are not conductors at any state • Examples; O2, CO2, C2H6, H2O, SiC

  26. Covalent Bonds

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

  28. COVALENT BONDin elements when electrons are shared equally H2 or Cl2

  29. 2. Covalent bonds- Two atoms share one or more pairs of outer-shell electrons. Oxygen Atom Oxygen Atom Oxygen Molecule (O2)

  30. COVALENT BONDS in compounds when electrons are shared but shared unequally H2O

  31. - water is a polarmolecule because oxygen is more electronegative than hydrogen, and therefore electrons are pulled closer to oxygen.

  32. METALLIC BONDbond found in metals; holds metal atoms together very strongly

  33. Metallic Bond • Formed between atoms of metallic elements • Electron cloud around atoms • Good conductors at all states, lustrous, very high melting points • Examples; Na, Fe, Al, Au, Co

  34. Ionic Bond, A Sea of Electrons

  35. Metals Form Alloys Metals do not combine with metals. They form Alloys which is a solution of a metal in a metal. Examples are steel, brass, bronze and pewter.

  36. Compounds and Their Bonds Ionic Compounds Naming Ionic Formulas

  37. Ionic Compounds • Attraction between + ions and - ions • Electrons go from metals to nonmetals electron transfer metal nonmetal ion+ ion– Electrons lost = Electrons gain

  38. Formulas of Ionic Compounds Formulas of ionic compounds are determined from the charges on the ions atoms ions  – Na  +  F :  Na+ : F :  NaF  sodium fluorine sodium fluoride formula Charge balance: 1+1- = 0

  39. Writing a Formula Write the formula for the ionic compound that will form between Ba2+ and Cl. Solution: 1. Balance charge with + and – ions 2. Write the positive ion of metal first, and the negative ion Ba2+ ClCl 3. Write the number of ions needed as subscriptsBaCl2

  40. Learning Check Write the correct formula for the compounds containing the following ions: A. Na+, S2- 1) NaS 2) Na2S 3) NaS2 B. Al3+, Cl- 1) AlCl3 2) AlCl 3) Al3Cl C. Mg2+, N3- 1) MgN 2) Mg2N3 3) Mg3N2

  41. Solution A. Na+, S2- 2) Na2S B. Al3+, Cl- 1) AlCl3 C. Mg2+, N3- 3) Mg3N2

  42. Naming Binary Ionic Compounds • Contain 2 different elements • Name the metal first, then the nonmetal as -ide. • Use name of a metal with a fixed charge Groups 1A, 2A, 3A and Ag, Zn, and Cd Examples: NaCl sodium chloride ZnI2 zinc iodide Al2O3 aluminum oxide

  43. Learning Check Complete the names of the following binary compounds: Na3N sodium ________________ KBr potassium ________________ Al2O3 aluminum ________________ MgS _________________________

  44. Solution Complete the names of the following binary compounds: Na3N sodium nitride KBr potassium bromide Al2O3 aluminum oxide MgS magnesium sulfide

  45. Learning Check A. The formula for the ionic compound of Na+ and O2- is 1) NaO 2) Na2O 3) NaO2 B. The formula of a compound of aluminum and chlorine is 1) Al3Cl 2) AlCl2 3) AlCl3 C. The formula of Fe3+ and O2- is 1) Fe3O2 2) FeO3 3) Fe2O3

  46. Solution A. The formula for the ionic compound of Na+ and O2- is 2) Na2O B. The formula of a compound of aluminum and chlorine is 3) AlCl3 C. The formula of Fe3+ and O2- is 3) Fe2O3

  47. Learning Check Name the following compounds: A. CaO 1) calcium oxide 2) calcium(I) oxide 3) calcium (II) oxide B. SnCl4 1) tin tetrachloride 2) tin(II) chloride 3) tin(IV) chloride C. Co2O3 1) cobalt oxide 2) cobalt (III) oxide 3) cobalt trioxide

  48. Solution Name the following compounds: A. CaO 1) calcium oxide B. SnCl43) tin(IV) chloride C. Co2O32) cobalt (III) oxide

More Related