What is the $IUPAC$ name of allylamine?

Explain the nomenclature of benzene-substituted compounds.

Give the structural formula for the following compounds:
$(i)$ Butanone
$(ii)$ Ethanamide

Write the $IUPAC$ names of the following structures:
$(i)$ $CH_3-CH=CH-CH(Br)-CH_3$
$(ii)$ $CH_2=C(CH_3)-CH(Br)-CH_3$
$(iii)$ $CH_3-CH=C(CH_3)-CH(Br)-CH_3$
$(iv)$ $CH_3-C(CH_3)=CH-CH_2Br$
$(v)$ $CH_3-CH=CH-CH_2Br$
$(vi)$ $CH_2=C(CH_3)-CH_2Br$

Identify the total number of substituents present in the given compound.

What is the $IUPAC$ name of the compound $OHC-(CH_2)_2-CH(CHO)-(CH_2)_2-CHO$?