Answer: Option (1) is the correct answer.
Step-by-step explanation:
A molecule of hydrazine has two nitrogen atoms and four hydrogen atoms. The formula of hydrazine is as follows.
The atomic number of nitrogen is 7 and it there are 5 electrons in its outermost shell. Hence, each nitrogen of hydrazine has one lone pair of electron, two hydrogen atoms are bonded to each nitrogen atom and there is one single bond between both the nitrogen atoms.
Thus, we can conclude that there are 1 pair of electrons are shared between the two nitrogen atoms.