Write the $IUPAC$ name of the following compound:
$OHC-CH_2-CH(CHO)-CHO$

Which of the following functional groups has the highest priority order for naming a polyfunctional compound?

Fill in the blanks:
$(1)$ ....... model indicates only bonds in a molecule.
$(2)$ Only ......... model of a molecule indicates both bonds as well as atoms.
$(3)$ In the nomenclature of cyclic compounds,the ....... prefix is written before the name of the simple chain containing alkane.
$(4)$ The names of $C_{20}H_{42}$ and $C_{30}H_{62}$ are ........... and .......... respectively.

The name of $CH_3-CH(CH_3)-CH(OH)-CH_3$ in the $IUPAC$ nomenclature system is

Which among the following is the correct $IUPAC$ name of isoamylene?

The $IUPAC$ name(s) of the following compound is(are):
$[A]$ $4-$methylchlorobenzene
$[B]$ $4-$chlorotoluene
$[C]$ $1-$chloro$-4-$methylbenzene
$[D]$ $1-$methyl$-4-$chlorobenzene