DNA Molicule

A molecule is defined as an electrically neutral group of at least two atoms in a definite arrangement held together by very strong chemical bonds.Molecules are distinguished from polyatomic ions in this strict sense. In organic chemistry and biochemistry, the term molecule is used less strictly and also is applied to charged organic molecules and bio-molecules

In the kinetic theory of gases. the term molecule is often used for any gaseous particle regardless of its composition. According to this definition noble gas atoms are considered molecules despite the fact that they are composed of a single non bonded atom

A molecule may consist of atoms of a single chemical element, as with oxygen (O2) or of different elements, as with water (H2O). Atoms and complexes connected by non covalent bonds such as hydrogen bonds or ionic bonds are generally not considered single molecules