What is the compound called if the remaining two valencies of a carbonyl group are satisfied by two alkyl groups?

Which among the following is an aromatic aldehyde?

Explain the $IUPAC$ nomenclature of aldehydes and ketones.

Match the formulas in column-$I$ with their corresponding names or functional group classifications in column-$II$.

column-$I$	column-$II$
$(i)$ $CH_3COCH_3$	$(a)$ Aldehyde,$(b)$ Ketone
$(ii)$ $CH_3CH_2CHO$	$(c)$ Propanone,$(d)$ Oxo
$(iii)$ $CH_3CH_2COOH$	$(e)$ One,$(f)$ al
	$(g)$ Propanoic acid

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

Write the structures of the following compounds:
$(i)$ $\alpha$-Methoxypropionaldehyde
$(ii)$ $3$-Hydroxybutanal
$(iii)$ $2$-Hydroxycyclopentanecarbaldehyde
$(iv)$ $4$-Oxopentanal
$(v)$ Di-sec-butyl ketone
$(vi)$ $4$-Fluoroacetophenone