VAN DER WAALS FORCES


Meaning of VAN DER WAALS FORCES in English

Relatively weak electrical forces that attract neutral (uncharged) molecule s to each other in gas es, liquefied and solidified gases, and almost all organic liquid s and solid s.

Solids held together by van der Waals forces typically have lower melting point s and are softer than those held together by ionic , covalent , or metallic bonds (see bonding ). The forces arise because neutral molecules, though uncharged, are usually electric dipole s, which have a tendency to align with each other and to induce further polarization in neighbouring molecules, resulting in a net attractive force. They are somewhat weaker than the forces involved in hydrogen bonding . See also Johannes D. van der Waals .

Britannica Concise Encyclopedia.      Краткая энциклопедия Британика.