What Are the Atoms of Ammonia?

When people speak of ammonia, they mean one of two things: a solution of ammonia gas in water or the gas itself.

Molecules

NH₃ and NH₄OH, are made of atoms. The gas has four atoms: one nitrogen (N) and three hydrogens (H). In ammonium hydroxide, there are five hydrogens, one oxygen (O) and one nitrogen.

Atoms

Atoms are the smallest particles of an element that can exist. Atoms bond together to form molecules. In the case of NH₃, three hydrogen atoms share their electrons with one nitrogen atom.

Geometry of Ammonium Hydroxide Molecules

In ammonium hydroxide, the nitrogen atom is attached to four hydrogen atoms forming a tetrahedron with a plus-one charge. Because it is in solution, the hydroxyl, or -OH⁻ part, is not attached.

Geometry of Ammonia Gas Molecules

Ammonia molecules are shaped like a tripod with its legs spread apart 107.8 degrees from each other. This is called a Trigonal Pyramid.

NH₃ Inversion

Ammonia gas molecules with the nitrogen at the top can flip so the hydrogen atoms are on top and the nitrogen atom is at the bottom. This can be compared to an umbrella blown by the wind so its canopy turns inside out, pointing upward instead of downward.

References

• Thermo Scientific

Resources

• U.S. Department of Energy