Friday is here, and the weekly 'A Taste of Science for the Weekend' column is back — issue 55.
This time: our love-hate relationship with carbon, and the reasons that make it a particularly fascinating element.
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Carbon is everywhere.
Although we're used to hearing about it in the context of carbon emissions, air pollution, and global warming, it remains one of the most essential elements for life on Earth.
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An organic compound contains carbon and hydrogen.
Animals are built from organic compounds, and even our DNA cannot exist without carbon, which is one of its central components.
Carbon has 4 electrons available to form chemical bonds with other atoms — and that's where things start to get complicated.
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In a normal combustion process, carbon forms a double bond with each of two neighboring oxygen atoms, producing carbon dioxide — a gas that enhances the greenhouse effect but is not particularly dangerous to breathe.
In a combustion process where there isn't enough oxygen, carbon forms a triple bond with a single oxygen atom, yielding carbon monoxide: a colorless, odorless, and particularly dangerous gas.
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When carbon monoxide is inhaled and enters the bloodstream, it binds to hemoglobin, which is responsible for transporting oxygen throughout the body.
Carbon monoxide attaches to the oxygen-binding sites on hemoglobin with an affinity more than 200 times greater than that of oxygen.
Because hemoglobin carries carbon monoxide instead of oxygen, the vital supply of oxygen to cells is blocked — which can lead to death.
Carbon monoxide can form in faulty engines, or in fires in enclosed spaces where there is insufficient oxygen.
The way to 'fix' carbon monoxide is to combust it again in the presence of oxygen, converting it into carbon dioxide. The catalytic converter installed in cars serves exactly this purpose.
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The oceans, animals, and plants all act as carbon storage reservoirs.
The accumulation of dead animals and plants, layer upon layer, eventually transforms them into natural gas, coal, and oil.
When these fossil fuels are burned, the carbon is released into the atmosphere as enormous quantities of gas.
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Most of us also know carbon as diamond or graphite, depending on how the atoms are arranged in the material — and in recent years, also as carbon nanotubes: a particularly fascinating and promising material.
Dry ice is essentially carbon dioxide in solid form at very low temperature, and it undergoes a phase change directly from solid to gas at -78.5 degrees, without passing through a liquid intermediate stage.
Carbon is also used for radioactive dating (carbon-14), carbonating beverages, steel production, controlling chain reactions in nuclear reactors — and the list goes on.
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So even as humanity fights carbon emissions to prevent global warming, it's important to remember that carbon is still a fundamental element of life and an extraordinarily useful material.
All we need to do is use it wisely.
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In the video: fire, carbon, and plastic come together to pollute the landscape and the sunset in the background.
Shabbat Shalom 😊
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