Tag: oxygen atom

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One-Electron Difference Between Oxygen and Nitrogen

One-Electron Difference Between Oxygen and Nitrogen

How does a one-electron difference between oxygen and nitrogen allow life to exist on our planet? Why does the correct mix between those two elements in our atmosphere make it possible for us to be here?

Yesterday, we talked about covalent bonding in oxygen and nitrogen. We said that an oxygen atom needs to share two electrons with another oxygen atom to make a stable oxygen molecule. However, nitrogen needs to share three electrons with another nitrogen atom to complete the valence shell and create stability. So how can a single electron difference between oxygen and nitrogen be a big deal?

For oxygen or nitrogen to combine with other elements to form new compounds essential for life, the covalent bond between them must be broken. It takes about double the energy to break the triple bond between two nitrogen atoms as to break the double bond between two oxygen atoms. That means oxygen can be released to form other compounds much more easily.

What does it take to break the oxygen bond and combine it with another element? Apply some heat to combustible material, and you will find out. You will get fire, which is a chemical reaction involving rapid oxidation of the burning material. Much slower oxidation occurs when oxygen in your blood combines with nutrients in your body, giving you energy and generating body heat. Another slow form of oxidation is when iron combines with oxygen to form iron oxide, or rust.

If it were not possible to release oxygen from its molecular bond with relative ease, we would not have combustion to heat our homes, run our vehicles, or energize our bodies. Life would not be possible. However, nitrogen bonds are much harder to break, and nitrogen is also essential for life. Tomorrow we will look at how the one-electron difference between oxygen and nitrogen enables life on planet Earth.

— Roland Earnst © 2022

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The Atmosphere Is Fine-Tuned for Life

The Atmosphere Is Fine-Tuned for Life

Nitrogen and oxygen together make up about 99% of the air we breathe. The vast majority of our atmosphere is nitrogen. Oxygen is ten times as abundant as nitrogen in the universe, but it makes up only about 21 percent of our atmosphere. So, the less common element is the most abundant in our atmosphere. What does that mean to us? The bottom line is that the atmosphere is fine-tuned for life. Let’s examine that more carefully.

An atom of oxygen and an atom of nitrogen differ by only one proton and one electron. That may not seem like much, but it makes a world of difference. Both of those elements form diatomic molecules, meaning that two atoms bond together to make one molecule of oxygen or nitrogen.

Covalent bonding is the chemical bonding of atoms by equal sharing of electrons. That bond gives atoms stability in their outer, or valence, electron shells. Atomic stability requires eight valence electrons. The only elements with that number are the so-called “noble gases”–helium, neon, argon, krypton, and radon. For that reason, they are inert, refusing to combine with other elements. All other elements need electrons to complete the octet in their valence shells.

An oxygen atom has six electrons in its valence shell, so it needs to share two electrons to become stable. When an oxygen atom shares two electrons with another oxygen atom, they both become stable. Nitrogen, on the other hand, has only five valence electrons. Therefore, by forming a covalent bond with another nitrogen atom, sharing three electrons, both atoms complete their outer shell. In this way, our atmosphere is made up of stable diatomic oxygen and nitrogen molecules.

However, not all molecules are equally stable. That is where we see the atmosphere is fine-tuned for life. For example, oxygen molecules have a double bond sharing two electrons, but nitrogen atoms have a triple bond sharing three electrons for more stability. That difference may seem insignificant, but it is essential to make life possible. Come back tomorrow when we will explain what a difference it makes.

— Roland Earnst © 2022

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Oxygen Atom Design and Water

Oxygen Atom Design and Water
In our post for yesterday (July 7, 2018) we dealt with oxygen as a designed feature promoting life by allowing us to breathe. Another interesting design feature relates to the oxygen atom design and water. The oxygen molecule’s design allows water to have the properties that it has.

The oxygen atom has eight electrons in orbitals based on their energy with the electrons paired so that their magnetic polarities are balanced. Each electron is essentially a little magnet with a north and a south pole. When the electrons are together in a pair, one electron’s north pole matches up with the second electron’s south pole. In oxygen, the first two electrons are in what is called the S orbital. The next energy level out is also an S orbital with two electrons. The third energy level out from the nucleus is the P orbital. This orbital can hold six electrons, but oxygen has only four electrons left. Two of the electrons are paired, but the remaining two are unpaired. They orbit in a pattern at right angles to one another. These orbits are not spherical but in the shape of a dumbbell.

What is the importance of oxygen atom design and water? A water molecule consists of two hydrogen atoms attached to the oxygen atom in such a way that they pair up with the two unpaired electrons. That means the water molecule is polar in nature with the hydrogen atoms on one end of the molecule and the oxygen atom on the other. The bond angle of the hydrogen atoms would be 90 degrees except for the fact that they repel each other. The repulsion forces the angle out to 105 degrees. This design allows water to have its unique properties which allow life to exist on Earth.

When water freezes, the molecules spread out due to the polar nature of the water molecule. Because of that, ice is lighter than liquid water so lakes freeze on top instead of on the bottom. If lakes froze from the bottom up, life in the water would not be possible. Also because of the polar nature of the water molecule, water dissolves things like salt.

The unique properties of water are due to the design of the oxygen molecule. As a high school chemistry teacher I always enjoy teaching about the oxygen atom design and water. Students are enthralled at the design built into such a simple thing as an oxygen molecule. Almost every time I teach this unit I have some kid say something like, “Wow! Who thought this up?” But this is not the product of a human engineer. An Engineer far wiser than any human created the design of oxygen and built a world that can support life.
–John N. Clayton © 2018
The illustrations are from John N. Clayton’s book The Source: Eternal Design or Infinite Accident? The book goes into much more detail and is available HERE.