Covalent Compounds: Names & Formulas

Objectives By the end of the lesson you should be able to: Describe the differences between covalent and ionic bonds Name and make all types of ionic and covalent compounds

Ionic Compounds Always involve a metal and a non-metal Electrons are always transferred from the metal to the non-metal Create ions because losing and gaining electrons (charges result)

Covalent Compounds Always involves 2 or more non-metals Electrons are shared between the non-metals Occurs in all diatomic molecules DO NOT form ions!

Covalent Compound Examples Carbon monoxide CO Carbon dioxide CO2 Water H2O Dihydrogen dioxide H2O2 Dinitrogen tetrachloride N2Cl4 Phosphorus trihydride PH3 Can we see any patterns or notice anything interesting?

Naming Covalent Compounds Name first element Name second element with “ide” ending Add any needed prefixes

Prefixes IF first atom is 1 DO NOT add “mono” Change any “oo” to “o” Prefix # Atoms Mono 1 Di 2 Tri 3 Tetra 4 Penta 5 Hexa 6 Hepta 7 Octa 8 Nona 9 Deca 10 Change any “oo” to “o” I.E. monooxide = monoxide

Naming Covalent Compounds Examples Eg. CO carbon monoxide N2O3 dinitrogen trioxide CS2 carbon disulphide CCl4 carbon tetrachloride P4O10 tetraphosphorus decaoxide

Making Covalent Compounds Write each symbol Add any subscripts according to prefixes DO NOT reduce Examples Eg. Nitrogen tribromide NBr3 Dichlorine monoxide Cl2O Dinitrogen tetrachloride N2Cl4

Naming Covalent Compounds With Hydrogen Memorize: CH4 = methane NH3 = ammonia H2O = water

Summary IONIC “ide” endings Multivalent = Roman numerals transfer electrons Metal + non metal “ide” endings Multivalent = Roman numerals Polyatomics = brackets COVALENT Share electrons Two non metals “ide” endings prefixes