Chrome, Iridium, and BISMUTH are all brittle metallic elements. Chrome is a transition metal with the chemical symbol Cr and atomic number 24. It is a hard, lustrous, and corrosion-resistant element that is used in many industrial applications. Iridium is a chemical element with the symbol Ir and atomic number 77. It is a very hard, brittle, silvery-white transition metal of the platinum group. BISMUTH is a chemical element with the symbol Bi and atomic number 83. It is a brittle, mildly toxic, silver-white metal that is often found in its native form. All three of these elements are brittle metallic elements that have a variety of uses in industry.