Tennessine

Tennessine is a special element that scientists made in a lab. Its symbol is Ts, and it has the atomic number 117. This makes it one of the heaviest elements ever made. Tennessine was named after the U.S. state of Tennessee, where important research took place.

The discovery of tennessine was announced in Dubna, Russia, by scientists from Russia and America in April 2010. After many tests, science groups officially recognized tennessine as a new element in 2016.

Tennessine is unusual because it might be part of something called the "island of stability." This means that even though it is very heavy, some of its atoms can last for short periods—tens or hundreds of milliseconds. Scientists think tennessine behaves like a metal and is part of the group of elements called halogens, but its properties might be different because of forces inside its atoms.

Introduction

Tennessine is a special element that scientists made in a lab. It has the symbol Ts and the number 117. Tennessine was named after the U.S. state of Tennessee, where important research was done to find it.

History

See also: Timeline of chemical element discoveries

Pre-discovery

In 2004, scientists from the Joint Institute for Nuclear Research in Dubna, Moscow Oblast, Russia, planned to make a new element, number 117. They wanted to mix an element called berkelium with calcium. But they could not get enough berkelium from the Oak Ridge National Laboratory in Oak Ridge, Tennessee, United States. So they had to wait.

Discovery

In 2008, Oak Ridge started making berkelium again. Scientists from Oak Ridge, Vanderbilt University, and the Joint Institute for Nuclear Research worked together. In late 2008, they had enough berkelium to try. The experiment began in July 2009 in Russia. In early 2010, they said they had made element 117. They made it by mixing berkelium and calcium.

Confirmation

Later, scientists checked their work. They made one of the products of element 117 breaking apart. Its properties matched what they had seen. In 2012, they did the experiment again and got the same results. In 2014, scientists in Germany also made element 117 and confirmed it.

Naming

At first, element 117 was called ununseptium. In 2016, the team decided to name it tennessine, after the region of Tennessee, where important research happened. The symbol for tennessine is Ts. The official naming happened in 2017.

Predicted properties

We do not know much about tennessine or its compounds because it is very hard to make and it breaks down quickly. Because of this, we can only guess what tennessine might be like.

Nuclear stability and isotopes

Atoms become less stable as they get bigger. All atoms with more than 82 protons are not stable. This is because the protons push each other apart. Some scientists think that for atoms with 114 protons and 184 neutrons, the atom might stay together longer. This is called the "island of stability." Tennessine is one of the heaviest atoms made so far, and its known forms break down very quickly, in less than one second. However, this is longer than scientists thought before they made it.

One form of tennessine, called ²⁹⁵Ts, might last about 18 milliseconds. Scientists are trying to make this form using special reactions. Some calculations suggest that very heavy forms of tennessine might last much longer, but this is still just a guess.

Atomic and physical

Tennessine is thought to be in group 17 of the periodic table, below fluorine, chlorine, bromine, iodine, and astatine. These elements all have seven electrons in their outer shell. Tennessine, being very heavy, might show some metal-like properties. This is because as you go down the group, the elements tend to become more metallic.

Because tennessine is so heavy, its electrons move very fast, close to the speed of light. This changes how the electrons behave and could make tennessine act differently from the other elements in its group. For example, it might not easily gain an electron like the lighter halogens do.

Chemical

The known forms of tennessine break down too quickly to study its chemistry directly. However, scientists have made guesses about its chemical properties. Tennessine might not behave like the other elements in its group. For example, it might not easily gain an electron to complete its outer shell.

Tennessine might form different kinds of bonds compared to the other halogens. It might form bonds using different parts of its electrons, which could change how it reacts with other elements. Scientists predict tennessine could form compounds in different states, like +1, +3, and +5, but the +7 state seems unlikely.

The simplest compound of tennessine, called TsH, might have a longer bond than expected because of how its electrons behave. This could make the bond weaker than bonds in similar compounds of lighter elements.