Агульныя гукавыя файлы

Did you know about Helium ? Today we will learn about the amazing element Helium ! Helium is a colorless , odorless , and very light gas , it is the second element in the periodic table and its atomic number is 2 , it is one of the lightest elements in the universe ! Scientists first discovered helium in the sun before finding it on earth , the name helium comes from the Greek word Helios meaning sun , later scientists found helium in natural gas on earth ! Helium is very stable and does not rea