Examples of Compounds Representing Ionic, Covalent, and Metallic Bonding

Ionic Bonding:
MgO
Magnesium Oxide

FeS
Iron (II) Sulfide

LiH
Lithium Hydride


Covalent Bonding:
NF₃
Nitrogen Trifluoride


N₂O₄
Dinitrogen Tetroxide


OF₂
Oxygen Diflouride

Metallic Bonding:
CuZn
Copper Zinc

Ti₆O
Titanium Oxide.


You can tell the difference between Ionic, Covalent and Metallic bonding easily. Ionic bonding will always have the second element ending in -ide. With Covalent bonding, there will always be a prefix in either one or both of the elements (example: mono-one. di- two. etc). With Metallic Bonding, there will always be a number of different elements. 


Work Cited:
http://www.chemistry.wustl.edu/~courses/genchem/Tutorials/Naming/covalent.htm
http://www.ausetute.com.au/namiform.html