4.1b Characteristic of ionic compounds

Ionic compounds usually have these characteristics:

• high melting and boiling point
• more soluble in water than in non-polar solvents. (A few exception to this trend thou) 
• They conduct electricity when molten or in aqueous solution but not when solid.

Physical properties of ionic compounds depend on how strong the ionic bond is.

Stronger bond = higher melting and boiling points = less volatility (less likely to vaporize) = more solubility (easy to dissolve) in water

In short, for stronger bond look for 

1. More charges  Eg. Ca2+ make stronger bond than Na+

2. Smaller atomic radius   Eg. Na+ make stronger bond than Rb+

Why? (You don't have to know this following part but math makes sense to some people)