chromium sesquioxide

  • 11Curium — This article is about the chemical element. For the ancient city located in Cyprus, see Kourion. americium ← curium → berkelium …

    Wikipedia

  • 12Iridium — (pronEng|ɪˈrɪdiəm) is a chemical element that has the symbol Ir and atomic number 77. A very hard, brittle, silvery white transition metal of the platinum family, iridium is the second densest element and is the most corrosion resistant metal,… …

    Wikipedia

  • 13North America — North American. the northern continent of the Western Hemisphere, extending from Central America to the Arctic Ocean. Highest point, Mt. McKinley, 20,300 ft. (6187 m); lowest, Death Valley, 276 ft. (84 m) below sea level. 400,000,000 including… …

    Universalium