Tennessine and the Synthesis of Element 117: Origins, Chemistry, and Speculation

Overview

In this Periodic Videos segment the host discusses element 117, tennessine, including its pronunciation and the origin of its name tied to Tennessee and the Oak Ridge National Laboratory. The synthesis route is described as belkelium being bombarded by calcium 48 to produce tennessine, illustrating how superheavy elements are created. The discussion then turns to speculative chemistry for this heavy halogen and the limitations of the experiments.

• Origin of the name linked to Oak Ridge and Tennessee
• Calcium 48 used to synthesize tennessine from berkelium
• Speculations on color and bonding for a halogen at the end of the periodic table
• Experimental limitations that prevent two atom diatomic species from existing in the same time

Introduction to the Segment

The video opens with a discussion of how to pronounce the element 117 name and explains the historical tie to the state of Tennessee and the Oak Ridge National Laboratory. It frames tennessine as a symbol of the enduring link between science and place, a point underscored by the lab where berkelium used in the synthesis was prepared. The presenter then outlines the basic chemistry question associated with tennessine as a halogen and the curiosity about its color and reactivity at extreme atomic numbers.

Naming and Geographic Connection

The host highlights that the element is named after Tennessee, a nod to the Oak Ridge facility where the berkelium used to prepare the heavy target was produced. This connection between location and discovery is presented as a reminder of the collaborative and infrastructural nature of modern chemistry and nuclear science.

How Tennessine is Made

The synthesis is described as colliding a very heavy berkelium target with a relatively light calcium isotope, calcium-48. This heavy ion reaction yields element 117, tennessine, illustrating the techniques used to create new elements far beyond the stable elements on the periodic table. The discussion emphasizes the high costs and complexities of producing such superheavy elements and the need for large accelerator facilities to enable these rare reactions.

Speculations on Chemistry and Color

The video shifts to speculative chemistry and what tennessine might look like in practice. By tracing the color trends of the halogens down the group fluorine, bromine, and iodine, the presenter ponders whether tennessine could be colorless, greenish, red, or even a black gas. The possibility of novel chemistry at the far end of the periodic table excites the imagination about what actual compounds might exist and how tennessine two atom diatomic molecules might behave.

Bonding and Diatomics

A key point is the difficulty of creating two identical tennessine atoms to form a diatomic molecule. The segment suggests that the bond between two tennessine atoms would be extremely weak and that an actual tennessine two may not be observed in a stable diatomic state. The discussion also touches on the idea of possible very weak interatomic bonds similar to helium bonds in other contexts.

Flight of Fancy and Potential Compounds

Beyond the diatomic question, the presenter imagines what compounds involving tennessine could look like. One imagined compound is francium tennesside, an analogue to common alkali halides like sodium chloride, but with the highly reactive francium and tennessine. The prediction suggests that such a compound could form flexible crystals, even springs, though the intense radioactivity of francium would make practical work impossible before any tangible object could be made.

Visual Experiments and Final Reflections

The segment shifts to a separate demonstration of liquid fluorine, noting the surprising appearance of a dark yellow color and contrasting it with expectations of pale green. The speaker reflects on the difficulty of visualizing liquid fluorine and acknowledges not having direct experience with liquid chlorine. The final lines touch on archival notes and the attempt to preserve the speaker’s work for future reference, underscoring the human element in scientific legacy.

Overall Takeaway

The video blends scientific explanation with imaginative speculation about a heavy element at the edge of chemical understanding, while also grounding the discussion in the real world of research infrastructure and archival memory. It serves as a reminder that breakthroughs in chemistry often come from a combination of careful experimental technique and creative hypothesis about how extreme elements might behave.