Helium (He) is the second-most abundant element in the universe, after hydrogen, and accounts for about 25 per cent of the elements in the universe. Most of the helium in the universe was created in the Big Bang, but it is also obtained as the product of hydrogen fusion in stars. The Darmstadtium is a chemical element with the symbol Ds and atomic number 110 . The very small atomic radius of osmium results in a small metal-metal separation. This small atomic separation alongwith osmium's relatively high atomic number gives rise to osmium's highest density. In group 1A, francium is more electropositive than ceasium but, not stable as it is highly radioactive (maximum half-life of only 22 minutes).