Write the resonance strucrures of `CH_(2) = CH - CHO` and compare their stabilities.

Explanation

The compound is a resonance hybride of three structures:

The stability order of these structures : `IgtIIgtIIIgt`. The unchanged structure (I) is the most stable one. The charged structure (II) is moderately stable because the more electronegative oxygen atom bears the negative charge and the less electronegative carbon atom bears the positive charge. Also the octet of carbon is not filled up. the charged structure (III) is the least stable because the more electronegative O - atom bears the positive charge and the less electronegative C - atom bears the negative charge. Also, the octect of the O - atom is not filled up.