A chemical bond forms when valence electrons are transferred (ionic) or shared (molecular) between atoms.
Bonds are formed to fill their highest energy level (often called and Octet). Noble gases have octets.
Ionic Bond—a strong bond between a metal cation (positive ions) and non-metal anion (negative ions).
Molecular (Covalent) Bond—a semi-strong bond between two non-metals.
Ion—atoms that have a charge (+ or -).
Lost electron = + charge = cation.
Gained electron = - charge = anion.
Properties of Ionic and Molecular Compounds
|Property||Ionic Bonds||Covalent Bonds|
|State||crystalline solids||solids, liquids, gases|
|Solubility||Usually dissolves in water but not in non-polar liquids||Usually soluble in non-polar liquids but not in water|
|Conductivity||Conducts electricity when melted or dissolved in water.||Does not conduct electricity.|
|Hardness||Hard and brittle||For covalent solids - usually soft|