Argon is an inert gas in group VIII A of the periodic table with atomic number 18, an atomic weight of 39.948, and a density of 1.40 Mg/m 3. In the solid state it forms an fcc crystal with a melting ...

There are currently 118 known elements on the periodic table, and we've put 20 of them ... Do you know what element Ar is? Ar ...

The noble gases (Helium, Neon, Argon etc.) were not discovered until much later ... Unfortunately for Meyer, his work wasn’t published until 1870, a year after Mendeleev’s periodic table had been ...