<p>An element belonging to the platinum group of metals, palladium (Kr4d<sup>10<sup>) (CAS 7440-05-3) is steel-white in color, except in powder form when it appears black. Palladium resists tarnishing in air and, if annealed, is soft and ductile.&nbsp;Palladium has the lowest density and melting point of the palladium metals and is the most reactive. At room temperature, palladium absorbs up to 900 times its own volume of hydrogen.<p> <p><a href="searchbrowsecategoryusen80014055">Transition Metal Salts <a>&gt; <a href="searchbrowsecategoryusen80014042">Metal Alloys&gt;<a><p> <p><strong>Phase at STP: <strong>Solid<p> <p><strong>Common Oxidation States: <strong>+2,4<p> <p><strong>Number of Valence Electrons:<strong> 10<p> <p><strong>Electronegativity (Pauling): <strong>2.2<p> <p><strong>First Ionization Energy: <strong>192 kcalmole<p> <p><strong>Covalent Radius: <strong> 1.28 Angstroms<p> <p><strong>Melting Point: <strong>1554.9&deg;C<p> <p><strong>Boiling Point: <strong>3167&deg;C<p> <p><strong>Density: <strong>12.02 gcm<sup>3<sup><p> <p><strong>Crystal Structure: <strong>Cubic, face-centered<p>