LECTURE 08 Covalent bonding

LECTURE 08 Covalent bonding - SUMMARY FROM LAST CLASS Ionic...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Dr. P. Lucas U of A MSE 110 Ionic Bonding SUMMARY FROM LAST CLASS The atomic radius decreases along a period Cations are smaller and anions bigger than the corresponding atom. The electronegativity is defined as the ability of an atom in a bond to attract electrons to itself. It increases along a period. The greater the difference in electronegativity between two atoms, the greater the ionic character of the bond. The ionic bond distance R o corresponds to the minimum bond energy at the equilibrium between electronic cloud repulsion and Coulombic attraction. The ionic bond strength decrease with ionic size. In the ionic solid, the charge of the anions must compensate the charge of the cations so that the composition is given by X n+ m L m- n . Ionic solids are brittle and have high melting points. Solvents of high dielectric constant ε like water decrease the Coulombic energy and dissolve ionic solids n rep R C E = R q q E o att πε 4 2 1 =
Background image of page 1

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

View Full DocumentRight Arrow Icon
U of A MSE 110 COVALENT BONDING Covalent bonding: electrons sharing. Atoms with similar electronegativity form covalent bonds. They can not be distinguished as belonging to one or the other atom any more. Both electrons reside in a molecular orbital, equivalent to an atomic orbital but extending over several nucleus. The two electrons participating in the covalent bond are then delocalized over the two nucleus. Electronic density plot of SCl 2 The electronic density is distributed along the bond between the two atoms. S Cl Cl Lewis electron dot diagram of SCl 2 The covalent bond is then described as two atoms combining or sharing two electrons to form a bond. This is done so as to satisfy the octet rule as described on the
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 10/06/2009 for the course MSE 110 taught by Professor Lucas during the Spring '08 term at Arizona.

Page1 / 12

LECTURE 08 Covalent bonding - SUMMARY FROM LAST CLASS Ionic...

This preview shows document pages 1 - 3. Sign up to view the full document.

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