Tennessine (Ts) is a synthetic, superheavy chemical element with the atomic number 117. It was first synthesized in 2010 through a collaboration between Russian and American scientists, and its existence was officially recognized in 2016. The element was named Tennessine to honor the contributions of research institutions in the state of Tennessee to superheavy element research. Describing Tennessine’s appearance is challenging, as its extreme instability prevents direct observation.
Tennessine’s Place in the Periodic Table
Tennessine is located in Group 17 of the periodic table, placing it among the halogens, which include fluorine, chlorine, bromine, iodine, and astatine. It resides in Period 7, directly below astatine.
Based on its position directly below astatine, Tennessine was initially expected to exhibit halogen-like chemical properties, such as having seven valence electrons. However, for elements as heavy as Tennessine, relativistic effects significantly alter electron behavior. These effects, where electrons move at speeds approaching the speed of light, can cause deviations from typical periodic trends.
Predicted Physical Characteristics
While Tennessine is classified as a halogen, theoretical predictions suggest its physical characteristics are influenced by relativistic effects, leading to properties that may differ from lighter halogens. Scientists predict Tennessine to be a solid at room temperature with a dark, possibly metallic, appearance, unlike lighter halogens that can be gaseous, liquid, or solid with varying colors.
Its density is estimated to be between 7.1 and 7.3 grams per cubic centimeter. Predicted melting points range from 350 to 550 degrees Celsius, and boiling points are estimated around 610 degrees Celsius. These values are higher than those of astatine and other lighter halogens, following a general periodic trend. The strong relativistic effects for Tennessine mean that it might behave more like a metalloid or even a metal, rather than a nonmetal halogen.
Why Direct Observation Isn’t Possible
Direct observation of Tennessine is not feasible. As a synthetic element, Tennessine does not occur naturally. It is created in laboratories by bombarding berkelium-249 with calcium-48 ions in particle accelerators, yielding only a few atoms at a time.
Tennessine is highly unstable and radioactive. Its most stable known isotope, Tennessine-294, has an approximate half-life of only 78 milliseconds. This extreme instability means created atoms exist for a fleeting moment before decaying, preventing accumulation for macroscopic observation or detailed study.
The Significance of Superheavy Element Research
Despite the challenges in observing Tennessine directly, research into superheavy elements holds considerable scientific importance. This work expands our understanding of nuclear physics and the fundamental forces that govern atomic nuclei. By creating and studying these ephemeral elements, scientists can explore the limits of the periodic table and test theoretical models of atomic structure and stability.
A significant aspect of this research is the search for the “island of stability,” a theoretical region where certain superheavy elements are predicted to have significantly longer half-lives. Discovering elements within this island could lead to new insights into nuclear stability and enable more detailed chemical experiments on these exotic atoms.