NH4+ and NH3 are an acid-conjugate base pair, since NH4+ is an acid, while NH3 is its conjugate base (since it is without the H+).
H2O and H3O+ can also be considered an acid-conjugate base pair, since H3O+ is an acid, while H2O would be its conjugate base. (But if only 1 answer is to be selected, it should be the NH4+ and NH3)
NH4+ and H3O+ are both acids, and both H2O and NH3 can be considered bases.
Volume of osmium = 1.01(0.223)(0.648) = 0.14595 cm3
Density = mass / volume
So density x volume = mass of osmium
22.6 x 0.14595 = 3.29845 g
Substances that are less dense than water will FLOAT and substances with a density that is greater than 1.00g/ml will SINK.
http://www.its.org/content/watch-kansas-city-chiefs-vs-cleveland-browns-live-stream-free-nfl