The answer to this question depends a bit on what exactly is meant by "identified."
There can also be some grey area as far as what is considered to an ionic compound. Here are some strategies for different contexts...
If dealing with nomenclature, ionic compounds will include a metal listed as the first element in a compound. It is also possible
an ionic compound to list a positively charged polyatomic ion (such as
If dealing with a bonding context, please consider the electronegativity difference between the two elements which are bonding. Many sources will say that a difference in electronegativity of >2.0 Pauling units is considered ionic although some sources may give a different cut off value - check your text book or the criteria given by your teacher for this.
If in a lab setting, ionic compounds will typically have very high melting points, many will dissolve in water and many will conduct electricity in the dissolved or molten state.