Forms of Chemical Bonds

1. Forms of Chemical Bonds • There are 2 forms bonding atoms: • Ionic—complete transfer of 1 or more electrons from one atom to another (one loses, the other gains) • Covalent—(molecular) some valence electrons shared between atoms

2. Covalent (Molecular) Compounds

3. Covalent / Molecular Bonds • The chemical bond that results from sharing electrons is a covalent bond. • A molecule is formed when two or more atoms bond covalently. • The majority of covalent bonds form between atoms of nonmetallic elements.

4. Molecular compound- -composed of molecules-Have low melting & boiling points-Are usually made up of two or more NONMETALS Sugar, a compound made of carbon, hydrogen and oxygen, melts easily in a hot pan.

5. Single Covalent Bonds When only one pair of electrons is shared, the result is a single covalent bond.

6. Multiple Covalent Bonds Double bonds form when two pairs of electrons are shared between two atoms. Triple bonds form when three pairs of electrons are shared between two atoms.

7. Diatomic ElementsCertain elements are only stable in pairs or with other elements in a compound. These elements are called the diatomic elements.

8. diatomic molecule –consists of two atoms of the same element (O2 andH2)

9. There are 7 diatomic elements:Bromine, Iodine, Nitrogen, Chlorine, Hydrogen, Oxygen, and Fluorine(Memory trick: HBrONClIF or 7th Heaven)

10. LET’S FIRST REVIEW IONIC BONDING

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

12. K F

13. K F

14. K F

15. K F

16. K F

17. K F

18. _ + K F

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

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

21. So what are covalent bonds?

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

23. But rather than losing or gaining electrons, atoms now share an electron pair.

24. The shared electron pair is called a bonding pair

25. Chlorine forms a covalent bond with itself Cl2

26. How will two chlorine atoms react? Cl Cl

27. Cl Cl Each chlorine atom wants to gain one electron to achieve an octet

28. Cl Cl Neither atom will give up an electron – chlorine is highly electronegative. What’s the solution –what can they do to achieve an octet?

29. Cl Cl

30. Cl Cl

31. Cl Cl

32. Cl Cl

33. Cl Cl octet

34. Cl Cl octet

35. Cl Cl The octet is achieved by each atom sharing the electron pair in the middle

36. Cl Cl The octet is achieved by each atom sharing the electron pair in the middle

37. Cl Cl This is the bonding pair

38. Cl Cl It is a single bonding pair

39. Cl Cl It is called aSINGLE BOND

40. Cl Cl Single bonds are abbreviated with a dash

41. Cl Cl This is the chlorine molecule, Cl2

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

50. O O