Ytterbium
Links
Visual Elements: Ytterbium
http://www.chemsoc.org/viselements/pages/ytterbium.html
Image, physical information, and ionisation energies.
It's Elemental: Ytterbium
http://education.jlab.org/itselemental/ele070.html
Basic physical and historical information.
ChemicalElements.com: Ytterbium
http://www.chemicalelements.com/elements/yb.html
Basic information, atomic structure, and isotopes.
Ytterbium
http://www.scescape.net/~woods/elements/ytterbium.html
Data tables and historic information.
EnvironmentalChemistry.com: Ytterbium
http://environmentalchemistry.com/yogi/periodic/Yb.html
Atomic structure, chemical and physical properties, and table of nuclides.
WebElements: Ytterbium
http://www.webelements.com/webelements/elements/text/Yb/key.html
Extensive information on history, uses, occurrence, compounds, and properties.
Lenntech: Ytterbium
http://www.lenntech.com/Periodic-chart-elements/Yb-en.htm
Physical data, chemical properties, health and environmental effects.