11. I mean, zirconia is zirconium oxide ( ZrO 2 ), and zirconium is a metallic element . 12. Only fluorine is more reactive among non-metallic elements . 13. A more modern definition is a material that contains metallic and non-metallic elements ( usually oxygen ). 14. They said they were also questioned about sales of magnesium, a metallic element used in incendiary bombs. 15. The wooden and metallic elements of the sala are as well as antique as the house itself. 16. Copper is one of a few metallic elements with a natural color other than gray or silver. 17. Station columns were made of a blue-gray veined marble reminiscent of the sky with decorative shiny metallic elements . 18. Aluminium is a light metallic element . 19. -- Hexavalent chromium : A form of the metallic element chromium found in speciality paints and cement or concrete. 20. In metallocene names, the prefix before the "-ocene " ending indicates what metallic element is between the Cp groups.
