What percentage of the atmosphere is nitrogen?

Nitrogen is used to produce which of the following?

Free nitrogen is converted or fixed into a usable form through what process?

The majority of nitrogen fixation happens when ___________ convert atmospheric nitrogen (N2) into ammonia (NH3).

Ammonia is toxic to plants. The ammonia must be converted into a more useful form by _____________ in the soil.

Bacteria converts ammonia into nitrates for plants to uptake in a process known as _____________.

When a plant or animal dies, or an animal defecates, decomposers convert nitrogen back into which of the following?

Reductions of nitrates or nitrites by bacteria that usually results in the escape of nitrogen into the air is known as what?

The nitrogen cycle has no beginning or end.

Consumers can get nitrogen directly from the atmosphere.

Plants and animals benefit from nitrogen-fixing bacteria.

When _____________ strikes, the high temperature affects the surrounding air, causing _____________ oxide and acid to fall to the ground for plants to use.

Nitrogen as a gas is usable for all living organisms.

Symbol for nitrogen.

Symbol for ammonia.

Nitrogen can be found in human DNA.