Ytterbium Element Overview and Chemical Properties

The chemical element ytterbium has the symbol Yb and atomic number 70. It is the fourteenth and penultimate element in the lanthanide sequence, and its +2 oxidation state is the basis for its relative stability. Its most common oxidation state, like that of the other lanthanides, is +3, as seen in its oxide, halides, and other compounds. Soluble ytterbium compounds form complexes with nine water molecules in an aqueous solution, similar to other late lanthanide compounds. Its density, melting, and boiling points vary greatly from those of most other lanthanides due to its closed-shell electron structure.

In 1878, the Swiss chemist Jean Charles Galissard de Marignac isolated an independent component from the rare earth "erbia," which he called "ytterbia" after Ytterby, the Swedish village near where he discovered the new erbium component. He assumed that ytterbia was a compound of ytterbium, a new element he had discovered. This article will study the Physical Properties of Ytterbium, the Chemical Properties of Ytterbium, and the Uses of Ytterbium.

Characteristics of Ytterbium

Physical Properties of Ytterbium

• When pure, ytterbium is a smooth, malleable, and ductile chemical element with a bright silvery lustre. It's a rare earth element that dissolves easily in heavy mineral acids. It oxidises slowly in the air and reacts slowly with cold water.

• At temperatures above 1.0 kelvin, ytterbium is paramagnetic, unlike the other rare-earth metals, which have antiferromagnetic and/or ferromagnetic properties at low temperatures. The alpha allotrope, on the other hand, is diamagnetic. Ytterbium has the lowest liquid range of all the metals, with a melting point of 824 °C and a boiling point of 1196 °C.

Chemical Properties of Ytterbium

• In the presence of sunlight, ytterbium metal tarnishes steadily, acquiring a golden or brown hue. In the presence of oxygen, finely scattered ytterbium readily oxidizes. A luminous emerald-green flame is produced by combining powdered ytterbium with polytetrafluoroethylene or hexachloroethane. Ytterbium reacts with hydrogen to form non-stoichiometric hydrides in a variety of ways. In water, ytterbium dissolves slowly but rapidly in acids, releasing hydrogen gas.

2 Yb (s) + 6 H2O (l) → 2 Yb(OH)3 (aq) + 3 H2 (g)

• Ytterbium is an electropositive metal that forms ytterbium(III) hydroxide when it reacts slowly with cold water and rapidly with hot water.

2 Yb (s) + 3 F2 (g) → 2 YbF3 (s) [white]

2 Yb (s) + 3 Cl2 (g) → 2 YbCl3 (s) [white]

• Since the ytterbium(III) ion absorbs light in the near-infrared spectrum but not visible light, ytterbia, Yb2O3, is white in colour and ytterbium salts are also colourless. Ytterbium readily dissolves in dilute sulfuric acid, forming solutions containing the colourless Yb(III) ions, which exist as nonahydrate complexes.

Uses of Ytterbium

1. Source of Gamma Rays

The 169Yb isotope (half-life 32 days) has been used as a radiation source in portable X-ray machines, along with the short-lived 175Yb isotope (half-life 4.2 days) produced by neutron activation during the irradiation of ytterbium in nuclear reactors. The gamma rays released by the source, like X-rays, pass through the body's soft tissues but are blocked by bones and other dense materials.

2. High-Stability Atomic Clocks

Ytterbium clocks have the highest level of stability, with ticks that are fewer than two sections of one quintillion.  Around 10,000 rare-earth atoms are cooled to 10 microkelvins (10 millionths of a degree above absolute zero) and trapped in an optical lattice—a sequence of pancake-shaped wells made of laser light—in the clocks built at the National Institute of Standards and Technology (NIST). Another laser, which "ticks" 518 trillion times a second, causes a change in the atoms' energy levels. The high stability of the clocks is due to a large number of atoms.

3. Doping of Stainless Steel

Ytterbium can also be used as a dopant in stainless steel to help refine grain refinement, strength, and other mechanical properties. Some ytterbium alloys have only been used in dentistry on a very limited basis.

4. It's also used in industry as a catalyst.

5. In dentistry, only a few Ytterbium alloys are used.

6. Ytterbium is an electropositive silvery-white metal that reacts with water to form ytterbium hydroxide.

7. Ytterbium is now used in the manufacture of memory devices and tunable lasers.

Did You Know?

Although ytterbium is chemically stable, it is protected from air and moisture by being stored in airtight containers and in an inert environment such as a nitrogen-filled dry box. While studies tend to suggest that the danger is limited, all ytterbium compounds are treated as highly toxic. However, ytterbium compounds irritate the skin and eyes of humans, and some of them may be teratogenic. Metallic ytterbium dust will spontaneously combust, releasing dangerous fumes. Ytterbium fires are impossible to put out with water, and only dry chemical class D fire extinguishers can do so.