2.  Formed between two non-metals  Valence electrons are shared between atoms

3.  Contain just two different types of non-metal elements

4.  Covalent compound have a few rules to naming to those of ionic compound  When non-metals combine they can form several different covalent compounds Example: Carbon and oxygen combine to form two common covalent compounds CO 2 and CO Each of these compounds have their own names

5. 1. Always write/name the element with more metallic character first. Metallic character increases going from right to left, and top to bottom on the Periodic Table.

6. 2. Then write/name the second (less metallic) element, changing the ending of its name to –”ide”

7. 3. Since nonmetals often combine in different proportions to form a number of different compounds, prefixes must be included in the names to indicate the numbers of each kind of atom present.

8. Number Prefix 1 mono- 6 hexa- 2 di- 7 hepta- 3 tri- 8 octa- 4 tetra- 9 nona- 5 penta- 10 deca-

9. P4S3 Tetraphosphorus trisulfide

10.  The mono- prefix is usually not used for the first element in the formula.  Example: BCl 3 boron trichloride

11.  Never use any prefixes at all for simple covalent compounds containing Hydrogen  Example: HF hydrogen fluoride

12.  The "o" and "a" endings of these prefixes are dropped when they are attached to "oxide."  Example: N 2 O 5 dinitrogen pentoxide

13.  Generally, they are in the same left-to-right order that they have on the periodic table, except that you would have to squeeze hydrogen in between nitrogen and oxygen.  Examples: NH3 ammonia CH4 methane H2O water

14.  Element that consists of two atoms combined Examples: F 2 fluorine N 2 nitrogen

15. SiF 4 silicon tetrafluoride

16. N2S3N2S3 dinitrogen trisulfide

17. HBr hydrogen bromide

18. Br 2 bromine

19. N 10 O 4 decanitrogen tetroxide

20. B2H6B2H6 diboron hexahydride

21. NBr 3 nitrogen tribromide

22. SCl 6 Sulfur hexachloride

23. P2O5P2O5 diphosphorus pentoxide

24. N3SN3S trinitrogen monosulfide

25. P8O7P8O7 octaphosphorus heptoxide

27. SbBr 3 Antimony tribromide

28. B 6 Si Hexaboron silicide

29. ClO 2 Chlorine dioxide

30. HI Hydrogen iodide

31. IF 5 Iodine pentafluoride

32. N2O3N2O3 Dinitrogen trioxide

33. NH 3 ammonia

34. PI 3 Phosphorus triiodide

35. P4S5P4S5 Tetraphosphorus pentasulfide

36. O2O2 oxygen

37. SeF 6 Selenium hexafluoride

38. Si 2 Br 6 Disilicon hexabromide

39. SCl 4 Sulfur tetrachloride

40. CH 4 methane

41. B 2 Si Diboron silicide

42. NF 3 Nitrogen trifluoride