Science / Periodic Table of Elements / Atomic Radius: One half the distance between nuclei of atoms of the same element, when the atoms are bound by a single covalent bond or are in a metallic crystal. The radius of atoms obtained from covalent bond lengths is called the covalent radius; the radius from interatomic distances in metallic crystals is called the metallic radius.
Science / Chemistry / Polyatomic Molecule: A polyatomic molecule is an uncharged particle that contains more than two atoms. MORE
Science / Chemistry / Polyatomic Ion: A polyatomic ion is a charged particle that contains more than two covalently bound atoms. See Polyatomic Ions for more. MORE