Which of the following elements was discovere | vedclass

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(C) The first noble gas to be discovered was helium by Pierre Janssen and Norman Lockyer in $1868-1869$.During a solar eclipse,spectroscopic investiga

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Helium

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(C) The first noble gas to be discovered was helium by Pierre Janssen and Norman Lockyer in $1868-1869$.During a solar eclipse,spectroscopic investigations of the Sun's chromosphere revealed a previously unobserved yellow spectral line. This line was found to be close in wavelength to the $D1$ and $D2$ Fraunhofer lines of sodium.The new line was assigned the designation $D3$. Since this line did not correspond to any known element on Earth at that time,it was concluded that it belonged to a new element,which was named helium (derived from the Greek word 'helios' meaning Sun).

Which of the following elements was discovered by the study of Fraunhofer lines?

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