This element is used as a shield against atmospheric contamination in gas tungsten arc welding. Radi
This element is used as a shield against atmospheric contamination in gas tungsten arc welding. Radioactive decay in the lithosphere from minerals containing thorium and uranium create most of this element on Earth. It was first observed as a yellow line in the solar spectrum. When it is cooled to below 4 Kelvin, the most common isotope of this element can creep up the walls of a container as a superfluid. Alpha particles are the nuclei of this element, the second most abundant in the universe. For 10 points, name this lightest noble gas with atomic number 2 and chemical symbol He.
This element is used as a shield against atmospheric contamination in gas tungsten arc welding.
helium [accept He before mentioned] 