- John Denver (Wikipedia)
Henry John Deutschendorf Jr. (December 31, 1943 – October 12, 1997), known professionally as John Denver, was an American singer and songwriter. He was one of the most popular acoustic artists of the 1970s and one of the bestselling artists in that decade. AllMusic has called Denver “among the most beloved entertainers of his era”.
- 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.
