Which of the following aldehydes contains two $-CHO$ groups in a molecule?

With reference to the carbonyl group,which statement$(s)$ is/are correct?
$A$. Carbonyl carbon is electrophilic
$B$. Carbonyl carbon is nucleophilic
$C$. Carbonyl oxygen is electrophilic
$D$. Carbonyl oxygen is nucleophilic

What is the common name of the compound $CH_2=CH-CHO$?

Which of the following is a simple (symmetrical) ketone?

Identify the functional group present in Vanillin.

Provide the $IUPAC$ name and structure for the following compounds:
$(i)$ Propanone
$(ii)$ Butanone
$(iii)$ Hexan$-3-$one
$(iv)$ $2,4-$dimethylpentan$-3-$one
$(v)$ Pentan$-3-$one
$(vi)$ $2-$methylcyclohexanone
$(vii)$ $4-$methylpent$-3-$en$-2-$one
$(viii)$ Benzophenone
$(ix)$ Acetophenone
$(x)$ $3-$methylbutan$-2-$one
$(xi)$ $5-$hydroxy$-5-$methylhexan$-3-$one
$(xii)$ $3-$oxobutanoic acid
$(xiii)$ $3,3-$dimethylheptan$-2,6-$dione.