compound (often used as a synonym for chemical) A compound is a substance formed when two or more chemical elements unite (bond) in fixed proportions. For example, water is a compound made of two hydrogen atoms bonded to one oxygen atom. Its chemical symbol is H2O.
element A building block of some larger structure. (in chemistry) Each of more than one hundred substances for which the smallest unit of each is a single atom. Examples include hydrogen, oxygen, carbon, lithium and uranium.
ferrofluid (also magnetic fluid) A liquid that responds to a magnetic field because magnetic particles have been mixed into it. The prefix, ferro , means iron and refers to the fact that magnetic materials contain iron.
iron A metallic element that is common within minerals in Earth’s crust and in its hot core. This metal also is found in cosmic dust and in many meteorites.
liquid A material that flows freely but keeps a constant volume, like water or oil.
magnet A material that usually contains iron and whose atoms are arranged so they attract certain metals.
magnetic field An area of influence created by certain materials, called magnets, or by the movement of electric charges.
particle A minute amount of something.
