Chapter 2.7

Chapter 2.7 - momentum in this atom. This bond due to...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
25 MSE 2090: Introduction to Materials Science Chapter 2, Bonding Secondary Bonding (I) Secondary = van der Waals = physical (as opposite to chemical bonding that involves e - transfer) bonding results from interaction of atomic or molecular dipoles and is weak, ~0.1 eV/atom or ~10 kJ/mol. Permanent dipole moments exist in some molecules (called polar molecules ) due to the asymmetrical arrangement of positively and negatively regions (HCl, H 2 O). Bonds between adjacent polar molecules – permanent dipole bonds –are±the± strongest among secondary bonds. Polar molecules can induce dipoles in adjacent non-polar molecules and bond is formed due to the attraction between the permanent and induced dipoles . Even in electrically symmetric molecules/atoms an electric dipole can be created by fluctuations of electron density distribution. Fluctuating electric field in one atom A is felt by the electrons of an adjacent atom, and induce a dipole
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 4
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: momentum in this atom. This bond due to fluctuating induced dipoles is the weakest (inert gases, H 2 , Cl 2 ). + _ + _ 26 MSE 2090: Introduction to Materials Science Chapter 2, Bonding Secondary Bonding (II) Example: hydrogen bond in water. The H end of the molecule is positively charged and can bond to the negative side of another H 2 O molecule (the O side of the H 2 O dipole) Hydrogen bond secondary bond formed between two permanent dipoles in adjacent water molecules. O H H Dipole + +-27 MSE 2090: Introduction to Materials Science Chapter 2, Bonding Secondary Bonding (III) Hydrogen bonding in liquid water from a molecular-level simulation Molecules: Primary bonds inside, secondary bonds among each other 28 MSE 2090: Introduction to Materials Science Chapter 2, Bonding Secondary Bonding (IV) The Crystal Structures of Ice Hexagonal Symmetry of Ice Snowflakes Figures by Paul R. Howell...
View Full Document

This note was uploaded on 02/14/2012 for the course MSE 2090 taught by Professor Leoindzhiglei during the Fall '10 term at UVA.

Page1 / 4

Chapter 2.7 - momentum in this atom. This bond due to...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online