Which is the main functional group in Acrolein?

Butanal is an example of

Which structure represents $3-$methyl$-2-$pentanone?

Number of oxygen atoms present in salicylaldehyde are

Which among the following is an aromatic aldehyde?

State True or False for the following statements:
$(i)$ Acetone is a propanone and there is an amide group in it.
$(ii)$ Acetone is dimethyl ketone.
$(iii)$ The formula of acetone is $CH_3COCH_3$.
$(iv)$ Acetone possesses a carbonyl group.