Some properties of the pnictogen trihydrides follow:[1] These gases have no smell in pure form, instead gaining it when in contact with air.
Ammonia has an infamous, intense odour resembling urine and/or fish, commonly the result of the decomposition of urea.
Phosphine smells like fish or garlic, and stibine like rotten eggs, similar to hydrogen sulfide and selenide.
Other effects of hydrogen bonding are a high dielectric constant as well as low values of density, viscosity, and electrical conductivity.
Hydrazine has physical properties that are remarkably similar to those of water: its melting and boiling points are 2.0 °C and 113.5 °C, the density of the solid at −5 °C is 1.146 g/cm3, while that of the liquid at 25 °C is 1.00 g/cm3.
Arsine and stibine are very easily oxidised to arsenic or antimony trioxide and water; a similar reaction happens with sulfur or selenium.