What you know about Helium ?
Atomic Number : 2 Atomic Weight : 4.002602 Melting Point : 0.95 K (-272.2°C or -458.0°F) Boiling Point : 4.22 K (-268.93°C or -452.07°F) Density : 0.0001785 grams per cubic centimeter Phase at Room Temperature : Gas Element Classification : Non-metal Period Number : 1 Group Number : 18 Group Name : Noble Gas What's in a name? For the Greek god of the sun, Helios . Say what? Helium is pronounced as HEE-lee-em . History and Uses : Helium, the second most abundant element in the universe, was discovered on the sun before it was found on the earth. Pierre-Jules-César Janssen, a French astronomer, noticed a yellow line in the sun's spectrum while studying total solar eclipse in 1868. Sir Norman Lockyer, an English astronomer, realized that this line, with a wavelength of 587.49 nanometers, could not be produced by any element known at the time. It was hypothesized that a new element on the sun was responsible for this mysterious y...