Answer
Helium, a colorless, odorless, and non-flammable gas, was discovered by Sir William Ramsay in 1895. While studying the mineral cleveite, Ramsay isolated a new gas that exhibited a bright yellow line in its spectrum, indicating the presence of a previously unknown element. He named the element helium, after the Greek word for "sun," as the yellow line in its spectrum resembled the prominent line observed in the Sun's spectrum.