what is sir william ramsay's most important achievement?

Answer 1

Sir William Ramsay (October 2, 1852 – July 23, 1916) was a Scottish chemist who discovered the noble gases and received the Nobel Prize in Chemistry in 1904 (along with Lord Rayleigh who received the Nobel Prize in Physics that same year for the discovery of argon).

He also isolated helium which had been observed in the spectrum of the sun but had not been found on earth. In 1910 he also isolated and characterized radon.