The common name for the element with atomic number 2 is helium. This lightweight, colorless, and odorless gas is the second most abundant element in the universe, primarily formed through nuclear fusion in stars. Helium is most commonly associated with party balloons because of its lower density compared to air, allowing balloons to float. In addition to its uses in entertainment, helium is instrumental in various scientific applications, including cryogenics, where it’s used to cool superconducting magnets, and as a lifting gas in airships. Additionally, it's important in the field of space exploration.