- Anna Eleanor Roosevelt (/ˈɛlɪnɔːr ˈroʊzəvɛlt/; October 11, 1884 – November 7, 1962) was an American political figure, diplomat, and activist. She served as the first lady of the United States from 1933 to 1945, during her husband President Franklin D. Roosevelt’s four terms in office, making her the longest-serving first lady of the United States. Roosevelt served as United States Delegate to the United Nations General Assembly from 1945 to 1952. President Harry S. Truman later called her the “First Lady of the World” in tribute to her human rights achievements.
- Radium (Wikipedia)
Radium is a chemical element; it has symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, but it readily reacts with nitrogen (rather than oxygen) upon exposure to air, forming a black surface layer of radium nitride (Ra3N2). All isotopes of radium are radioactive, the most stable isotope being radium-226 with a half-life of 1,600 years. When radium decays, it emits ionizing radiation as a by-product, which can excite fluorescent chemicals and cause radioluminescence. For this property, it was widely used in self-luminous paints following its discovery. Of the radioactive elements that occur in quantity, radium is considered particularly toxic, and it is carcinogenic due to the radioactivity of both it and its immediate decay product radon as well as its tendency to accumulate in the bones.
