Freeing Up Nitrogen Atoms

Nitrogen is an essential ingredient in biological molecules, such as proteins and DNA, but nitrogen must be in a free state for these molecules to form. By that, we mean nitrogen atoms that are not already bonded to each other, making them inert. Seventy-eight percent of our atmosphere consists of nitrogen, but nitrogen atoms in the air are bonded with other nitrogen atoms to form nitrogen molecules that are chemically inert. It takes enormous amounts of energy to tear apart nitrogen molecules, freeing up nitrogen atoms to bond with other elements.

A nitrogen atom can be useful for life when it bonds with three oxygen atoms to make nitrate. Nitrogen can also bond with three hydrogen atoms making ammonia, which is also useful for life. This is a complicated issue because Earth’s early atmosphere did not contain much oxygen, so the rock record shows nitrogen bonded to hydrogen atoms. Ammonia has a very low gram molecular weight, so it can escape Earth’s gravity. We see large amounts of ammonia in the atmospheres of our Jovian planets, but that is because their large masses provide enough gravity to hold on to the ammonia.

Humans create nitrogen fertilizer through chemical and electrical processes. But that method of freeing up nitrogen atoms is complex and requires a lot of energy. Scientists in the past have theorized that microbes could have been the method of nitrogen fixation, reducing the nitrogen to nitrates. This is a “chicken-egg” problem because nitrates had to be in existence for the microbes to exist. Freeing up nitrogen atoms would require some non-biologic processes. Studies have shown that electric discharges in lightning have enough energy to tear apart nitrogen molecules, but the rate is insufficient to account for all the nitrogen needed.

New research on volcanoes has shown that eruptions release oxygen and supply enough energy to tear apart nitrogen molecules that bond with oxygen. The nitrates produced would accumulate, allowing life to survive. Studies have shown that a strong volcanic eruption can produce about 60 million tons of nitrate. In 2022 the Tonga-Hunga Ha’apai volcano in Indonesia produced 400,000 discharges in one day.

As we learn more about the chemistry and physics required for freeing up nitrogen to allow life to exist on this planet, the complexity and design of the system astound many researchers. The Bible merely says God did it, but not how or what complexities were involved. Everywhere we look, we see that a wounder-working hand has gone before. Nitrogen is an excellent example of how much wisdom, power, and planning was required for a life-bearing planet to come into existence.

— John N. Clayton © 2023

Reference: Science News for June 3, 2023, page 7.