aatomeid (elektrone) kristallivõres kooshoidev keemiline side, vastastikjõud, mille korral aatom jagab naaberaatomiga ühte ja/või mitut valentselektroni (vt keemiline side), a chemical bond in which two or more atoms held together by the interaction of their outer electron clouds; a co-ordinate bond involves one atom donating a spare pair of electrons to form a covalent bond (see: chemical bond)