The rare radioactive substance made its way from the United States to Russia on a commercial flight in June 2009. Customs officers balked at accepting the package, which was ensconced in lead ...

On the periodic table, most elements have at least one stable form. But others have only unstable forms, all of which decay by emitting radiation and transforming into different elements until ...

“To develop the scientific temper, humanism and the spirit of inquiry and reform.” These words were crafted in 1976 in an amendment to India’s constitution. The constitution’s writers rightly saw the ...

118 elements and seven periods, though just one period of high school chemistry is enough to get confused by it. This week, we’re exploring the history behind the periodic table.

At the middle of the 19th century, 63 chemical elements were known to science. Before Mendeleev’s discovery, attempts at arranging them in some logical way were made by Johann Doebereiner (1829), ...