k

• carbonyl group 


  Carbon atom double-bonded to an oxygen atom
• Carbon–oxygen 


  double bond is polar
• Carbon–carbon 


  double bond is nonpolar
• carbonyl group 


  aldehydes, ketone, carboxylic acids, ester, amide
• aldehydes 


  Carbonyl is attached to at least one H atom
• Aldehyde


  CHO (RCHO)
• aldehyde 


  the carbonyl group is always located at the end of a hydrocarbon chain.