Group 0 or group 18 elements of the periodic table are collectively known as noble gases. These gases are also referred to as inert gases. By the time of writing total seven (7) noble gases have been discovered. They are Helium, Neon, Argon, Krypton, Xenon, Radon, and Oganesson.
Although helium is the first element in the noble gas group of the periodic table, it was not the first noble gas to be discovered. The first noble gas discovered was argon. Argon was discovered in 1894 by Lord Rayleigh and Sir William Ramsay. They both won the noble prize in 1904 for the discovery of argon. Lord Rayleigh received the prize in physics and Ramsay's award was in chemistry. Helium was discovered earlier in 1868 but in the Sun's spectrum, not on Earth. And nobody knew that helium is a noble gas then. It was only later in 1895 that helium was isolated in Earth by Sir William Ramsay.