|
|
| Holmium |
| Holmium is a chemical element in the periodic table that has the symbol Ho and atomic number 67. Part of the lanthanide series, holmium is a relatively soft and malleable silvery-white metallic element, which is stable in dry air at room temperature. A rare earth metal, it is found in the minerals monazite and gadolinite. |
| |
|
|
| Dysprosium |
| Dysprosium is a chemical element in the periodic table that has the symbol Dy and atomic number 66. Dysprosium is a rare earth element that has a metallic, bright silver luster, relatively stable in air at room temperature, but dissolving readily in dilute or concentrated mineral acids with the emission of hydrogen. It is soft enough to be cut with a knife, and can be machined without sparking if overheating is avoided. Dysprosium's characteristics can be greatly affected even by small amounts of impurities. |
| |
| Terbium |
| Terbium is a chemical element in the periodic table that has the symbol Tb and atomic number 65. Terbium is a silvery-gray rare earth metal that is malleable, ductile and soft enough to be cut with a knife. It is reasonably stable in air, and two crystal modifications exist, with a transformation temperature of 1289°C. |
| |
| Gadolinium |
| Gadolinium is a chemical element in the periodic table that has the symbol Gd and atomic number 64. Gadolinium is a silvery white, malleable and ductile rare earth metal with a metallic luster. It crystalizes in hexagonal, close-packed alpha form at room temperature; when heated to 1508 K, it transforms into its beta form, which has a body-centered cubic structure. |
| |
| Europium |
| Europium is a chemical element in the periodic table that has the symbol Eu and atomic number 63. Europium is the most reactive of the rare earth elements; it quickly oxidizes in air, and resembles Calcium in its reaction with water. Like other rare earths (with the exception of Lanthanum, Europium ignites in air at about 150 to 180°. It is about as hard as lead and quite ductile |
| |
| Samarium |
| Samarium is a chemical element in the periodic table that has the symbol Sm and atomic number 62. Samarium is a rare earth metal, with a bright silver lustre, that is reasonably stable in air; it ignites in air at 150°C. Three crystal modifications of the metal also exist, with transformations at 734 and 922°C, respectively. |
| |
| Promethium |
| Promethium is a chemical element in the periodic table that has the symbol Pm and atomic number 61. Promethium is a soft beta emitter; it does not emit gamma rays, but beta particles impinging on elements of high atomic numbers can generate X-rays. Little is known as of today about the properties of metallic promethium; two allotropic modifications exist, and promethium salts luminesce in the dark with a pale blue or greenish glow due to their high radioactivity. |
| |
| Neodymium |
| Neodymium is a chemical element in the periodic table that has the symbol Nd and atomic number 60. Neodymium, a rare earth metal, is present in misch metal to the extent of about 18%. The metal has a bright silvery metallic luster; however, being one of the more reactive rare-earth metals, Neodymium quickly tarnishes in air, forming an oxide that spalls off and exposes the metal to further oxidation. |
| |
| Praseodymium |
| Praseodymium is a chemical element in the periodic table that has the symbol Pr and atomic number 59. Praseodymium is a soft silvery metallic element, and belongs to the lanthanide group. It is somewhat more resistant to corrosion in air than europium, lanthanum, cerium, or neodymium, but it does develop a green oxide coating that spalls off when exposed to air, exposing more metal to oxidation. For this reason, praseodymium should be stored under a light mineral oil or sealed in plastic or glass. |
| |
| Cerium |
| Cerium is a chemical element in the periodic table that has the symbol Ce and atomic number 58. Cerium is a silvery metallic element, belonging to the lanthanide group. It is used in some rare-earth alloys. It resembles iron in color and luster, but is soft, and both malleable and ductile. It tarnishes readily in the air. |
| |
![[Valid RSS]](/_images/rss2logo.gif){kind=small}