Ammonia
Ammonia is a strong-smelling gas made of nitrogen and hydrogen that forms when waste breaks down in water.
When a block of cheese sits out in a warm kitchen, it slowly breaks down and gives off a sharp smell. That smell spreads from the cheese across the whole room. Ammonia works the same way. Waste breaks down in water and gives off ammonia gas, which drifts out in all directions.
Explaining ammonia by grade level
Dirty water from fish tanks can start to smell bad. That smell comes from waste that fish leave behind. Tiny life forms break down the waste and make a gas. That gas can hurt the fish if it builds up too much.
Projects that explore ammonia
Ammonia is a strong-smelling gas made of nitrogen and hydrogen that forms when organic waste breaks down in water. It is one of eight contaminants tested when comparing filtration, distillation, and solar pasteurization across tap water and Chicago River water. Distillation heats water into steam and collects it, and that process proved most effective at removing contaminants including ammonia nitrogen from both sources.
Ammonia forms when waste breaks down in water. Human activity near rivers adds waste that raises ammonia levels. Testing ammonia content upstream and downstream of a town shows whether people increase that pollution.
Ammonia forms when organic waste decomposes in water, and it can accumulate at different concentrations depending on depth. A diver collects water samples from four depths — 1 meter, 2 meters, 3 meters, and 4 meters — taking five samples at each level. Testing those samples for ammonia content alongside pH, turbidity, and nitrate reveals whether pollutants concentrate near the surface or sink as depth increases.
Fish produce waste that breaks down into ammonia in aquarium water, and that buildup changes the water's pH over time. Two tanks each hold three goldfish — one uses a sponge filter, the other an under-gravel filter. Testing pH and ammonia levels weekly for four weeks shows which filter keeps the water closer to its starting condition.