MCQ Detailed View

The element that was first discovered in the chromosphere of the Sun is helium. Its discovery is unique in the history of chemistry because it was identified in space before being found on Earth. The event took place in 1868, during a solar eclipse, when astronomers were studying the solar spectrum using spectroscopy. The French astronomer Jules Janssen and the English astronomer Joseph Norman Lockyer observed a bright yellow spectral line near the known sodium D-lines but slightly different in wavelength. Since this line did not match any element known on Earth at the time, they concluded it represented a new element. Lockyer named it “helium,” derived from the Greek word Helios, meaning “Sun.”

Helium was not discovered on Earth until 1895, when Scottish chemist Sir William Ramsay isolated it while treating the mineral cleveite with acid. This confirmed that helium was indeed a new element, both terrestrial and cosmic. The identification of helium through spectroscopy was a milestone because it proved that elements could be detected by their spectral lines even without direct physical samples.

The other options in the question—krypton, xenon, and neon—are also noble gases but were discovered much later on Earth through different experimental methods. Krypton and xenon were discovered in 1898 by Ramsay and Travers, while neon was discovered in 1898 as well. None of these were first identified in the Sun.

Helium remains the second most abundant element in the universe after hydrogen and plays a vital role in nuclear fusion processes within stars. Its unique discovery in the Sun’s chromosphere highlights the importance of spectroscopy in inorganic chemistry and astrophysics.