Ytterbium

Introduction

Ytterbium (Yb) is a chemical element with atomic number 70. It is a lanthanide and a rare-earth metal, named after the village of Ytterby in Sweden, where it was discovered. Ytterbium is a soft, malleable and ductile metal with a bright silvery luster when freshly cut. It is relatively stable in air, but reacts with water and acids to release hydrogen gas.

History

Ytterbium was discovered by the Swiss chemist Jean Charles Galissard de Marignac in 1878. He detected its presence in the mineral gadolinite, which was named after the Finnish chemist Johan Gadolin, who had discovered the first rare-earth element. Marignac named the new element "ytterbium", after Ytterby, the Swedish village where gadolinite was first found.

Properties and Characteristics

Ytterbium is a rare-earth metal with a bright silvery luster. It is soft, malleable and ductile, and can be cut with a knife. It has a melting point of 824 degrees Celsius and a boiling point of 1196 degrees Celsius. Ytterbium has two allotropes: a face-centered cubic (fcc) form that exists at room temperature, and a body-centered cubic (bcc) form that exists at high temperatures.

Ytterbium is relatively stable in air, but it tarnishes slowly in moist air. It reacts with water and acids to release hydrogen gas. Ytterbium has a low electrical resistivity and a high thermal conductivity, which makes it useful in certain electronic applications.

Occurrence and Production

Ytterbium is not found free in nature, but it occurs in several minerals, including xenotime, monazite, and euxenite. It is usually obtained from monazite sand, which contains about 0.03% ytterbium. The production of ytterbium involves the mining of monazite sand, followed by a series of chemical reactions to separate ytterbium from the other lanthanides.

Uses and Applications

Ytterbium has several uses in various fields. In metallurgy, it is used as an additive to improve the mechanical properties of certain alloys. In medicine, it is used in the treatment of certain types of cancer. In telecommunications, it is used in fiber optic cables and laser technology. In nuclear technology, it is used as a neutron absorber in nuclear reactors.

Health and Environmental Effects

Ytterbium is considered to be of low toxicity, but it can be hazardous if ingested or inhaled in large amounts. It can cause lung and skin irritation, and prolonged exposure can lead to lung and bone cancer. Ytterbium compounds can be harmful to the environment, especially aquatic ecosystems.