More than 4,000 naturally occurring minerals—inorganic solids that have a characteristic chemical composition and specific crystal structure—have been found on Earth. They are formed of simple ...

Scientists use the periodic table to quickly refer to information about an element, like atomic mass and chemical symbol. The periodic table’s arrangement also allows scientists to discern trends in ...

Uranium (chemical symbol U) is a naturally occurring radioactive element ... In addition to the uranium naturally found in minerals, the uranium metal and compounds produced by industrial activities ...