Helium was originally discovered on the sun by a French astronomer named Pierre-Jules-Cesar Janssen. Janssen made his discovery when he observed a yellow line within the sun's spectrum in 1868 during a solar eclipse. More »

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While observing a solar eclipse in 1868, astronomer Pierre Janssen noticed bright yellow lines in the Sun's chromosphere. He concluded that the chromosphere was gaseous and that it could be studied in the absence of an e... More »

The discovery of helium on Earth was made in the United Kingdom by Scottish chemist Sir William Ramsay in 1895. However, the element was first discovered on the sun by French astronomer Pierre Janssen. More »

The nucleus of helium contains two neutrons and two protons. Around the nucleus of helium there are two electrons in the 1s orbital. These have opposite spins. More »

Of all the elements of the periodic table, helium is the least reactive. It does not react with water, acids, halogens, bases or air. More »

One atom of helium has two protons in its nucleus. A neutral atom of helium also has two electrons. More »

A gas that has the opposite effect of helium on the human voice is xenon. Another gas that reverses the temporary high-pitched effect of inhaling helium is sulfur hexafluoride. Both gases are more dense than air and magn... More »