User:Praseodymium-141/Holmium

Sectioning

 * lead - ✅
 * physical properties - ✅
 * chemical properties - ✅ (includes oxidation states)
 * isotopes - ✅
 * history - ✅
 * occurrence and production - ✅
 * applications - ✅
 * biological role and precautions - ✅
 * prices - ✅
 * compounds - create

remember to say that test has been copied from Ho2O3 and Ho2S3.

Oxides and chalcogenides


Holmium(III) oxide is the only oxide of holmium. It changes color changes on the lighting conditions. In daylight, it is a tannish yellow color. Under trichromatic light, it is a fiery orange red, almost indistinguishable from the way erbium oxide looks under this same lighting. This is due to the sharp emission bands of the phosphors.

Other chalcogenides are known for holmium. Holmium(III) sulfide has orange-yellow crystals in the monoclinic crystal system, with the space group P21/m (No. 11). Under high pressure, holmium(III) sulfide can form in the cubic and orthorhombic crystal systems. It can be obtained by the reaction of holmium(III) oxide and hydrogen sulfide at 1325 °C. Holmium(III) selenide is also known. It is antiferromagnetic below 6 K.

Halides
All four trihalides of holmium are known. Holmium(III) fluoride is a yellowish powder that can be produced by reacting holmium(III) oxide and ammonium fluoride, then crystallising it from the ammonium salt formed in solution. Holmium(III) chloride can be prepared in a similar way, with ammonium chloride instead of ammonium fluoride. It has the YCl3 layer structure in the solid state. These compounds, as well as holmium(III) bromide and holmium(III) iodide, can be obtained by the direct reaction of the elements:


 * 2 Ho + 3 X2 → 2 HoX3

In addition, holmium(III) iodide can be obtained by the direct reaction of holmium and mercury(II) iodide, then removing the mercury by distillation.