MCQ Detailed View

The universe is made up of countless atoms forming stars, planets, and interstellar clouds. Among all known elements, hydrogen is the most abundant, making up about 75% of the universe's visible matter. This dominance is due to how the universe formed after the Big Bang, when simple elements were created in massive amounts.

Hydrogen is the lightest element, consisting of only one proton and one electron. Because of its simplicity, hydrogen was the first element to form when the early universe cooled down. Most stars, including our Sun, are primarily made of hydrogen gas. Inside stars, hydrogen atoms undergo nuclear fusion, combining to form helium and releasing enormous amounts of energy in the process. This is the source of starlight and heat.

Hydrogen is found in every corner of the cosmos—in stars, giant gas clouds, and even in the composition of water molecules on planets. It is essential for the formation of galaxies and planetary systems. Without hydrogen, stars could not shine, and heavier elements necessary for life would never have formed.

Other elements like helium, oxygen, and carbon are also present in space, but in much smaller quantities compared to hydrogen. Helium makes up around 24% of visible matter, while all heavier elements combined contribute only about 1–2%.

This question belongs to Physics, particularly the branch that studies the composition of matter, astronomy, and cosmology. Understanding the abundance of hydrogen helps explain how stars are born, how they evolve, and how the universe has developed over billions of years.

Hydrogen’s presence is not only a fundamental concept in physics but also a key to understanding the origin and structure of the cosmos itself.