Answer : The Lewis-dot structure of
molecule is shown below.
Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule. The valence electrons are represented by the 'dot'.
The given molecule is,

As we know that nitrogen has '5' valence electrons and chlorine has '7' valence electrons.
Therefore, the total number of valence electrons in butyne,
= 1(5) + 3(7) = 26
According to Lewis-dot structure, there are 6 number of bonding electrons and 20 number of non-bonding electrons.
In the image, the red color dots are the valence electrons of nitrogen and black color dots are the valance electrons of chlorine. And the lone pairs are also show.
The Lewis-dot structure of
is shown below.