{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Radius_Determination_F10

Radius_Determination_F10 - Si radius = 0.117nm Si – C =...

Info iconThis preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Radius Determination GLY 4200 Fall, 2010
Background image of page 1

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

View Full Document Right Arrow Icon
2 X-ray Diffraction Image Images like these can be used to determine crystal structures
Background image of page 2
3 Comparison of Radii
Background image of page 3

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

View Full Document Right Arrow Icon
4 Squashed versus Unsquashed Left, metallic or covalent radius Rght, Van der Waals radius
Background image of page 4
5 Radii Across a Row Diagram uses metallic radii for metallic elements, covalent radii for elements that form covalent bonds, and van der Waals radii for those (like the noble gases) which don't form bonds
Background image of page 5

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

View Full Document Right Arrow Icon
6 Coulomb’s Law F (Z 1 Z 2 )/r 2 where Z i = charge on each ion r = distance between ions
Background image of page 6
7 Covalent Radius Example Example: C-C spacing in diamond is 0.154nm Metallic Si-Si spacing is 0.234nm C radius = 0.077nm
Background image of page 7

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

View Full Document Right Arrow Icon
Background image of page 8
Background image of page 9

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

View Full Document Right Arrow Icon
Background image of page 10
Background image of page 11
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Si radius = 0.117nm Si – C = 0.194 nm predicted 0.193 nm observed 8 Electron Density Contour Map of LiF • Electron density (electrons/volume) is the preferred method of determining ionic radius 9 Electron Density Variation • Electron density variation between Li + and F-• Note the variation has a very flat bottom. • M, G and P indicate the true minimum, and the Goldshmidt and Pauling ionic radii 10 Ionic Radii versus CN 11 Ionic Character • Example: CaF Ca = 1.1 F = 4.0 • Difference = 2.9 Close to 88% ionic • Example: SiN Si = 1.8 N = 3.1 • Difference = 1.3 28% ionic...
View Full Document

{[ snackBarMessage ]}