Answer:
soft, low melting , a poor electrical conductor
Explanation:
In a solid crystal of NH3; there exist a covalent bonding in between the Nitrogen and the hydrogen atoms. Thus the NH3 solid crystal is soft due as a result of covalent bonding. Covalent bonds are formed between two or more atoms having zero or very small electronegativity difference.
However in a covalent bond, a low temperature of heat is sufficient in melting solid crystals of NH3.
SImilarly,in NH3 , the crystal structures , the crystal lattice of NH3 are fixed . Hence , the remain a poor conductor of electricity as they partially dissociate into ions in water.
Thus; A solid crystal of NH3 is soft,have a low melting and a poor electrical conductor.
