Most common elements in the universe
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Hydrogen and Helium: The Most Common Elements in the Universe
Hydrogen is by far the most abundant element in the universe, making up about 90% of all atoms and roughly 75% of the universe’s mass. Helium is the second most common, accounting for most of the remaining mass. Together, hydrogen and helium make up over 98% of all known matter in the universe, leaving less than 2% for all other elements combined SearsJr.2015Lehrer1999Cragg2019+4 MORE.
Other Abundant Elements: Carbon, Nitrogen, and Oxygen
After hydrogen and helium, the next most common elements in the universe are carbon, nitrogen, and oxygen. These elements, often referred to as CNO, are much less abundant but still play significant roles in the chemistry of stars and galaxies. Their presence is crucial for the formation of planets and life as we know it Lehrer1999Randich2021.
Rarer Elements and Their Origins
All other elements, including those essential for life and technology such as iron, silicon, and heavier metals, make up only a tiny fraction of the universe’s total mass. These heavier elements are primarily formed in stars through nuclear fusion and in supernova explosions, which scatter them into space Lehrer1999Randich2021Burbidge1957.
The Uneven Distribution of Elements
While Earth is rich in elements like oxygen, silicon, and iron, this is not representative of the universe as a whole. The chemical composition of the universe is dominated by hydrogen and helium, with heavier elements being much rarer and often concentrated in planets, stars, and other celestial bodies SearsJr.2015Lehrer1999.
Conclusion
In summary, hydrogen and helium are overwhelmingly the most common elements in the universe, making up more than 98% of all matter. Carbon, nitrogen, and oxygen follow but are much less abundant. All other elements, including those vital for life and technology, are present only in trace amounts compared to hydrogen and helium SearsJr.2015Lehrer1999Cragg2019+6 MORE.
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