Media New Atlas reported that when it goes deep into the atomic scale, things happen much faster than we normally see. This makes it difficult to really see what happens during a chemical reaction, so researchers at Harvard University have found a way to slow down. By cooling the molecules to a temperature 500 nanometers above absolute zero, the team was able to perform the coldest chemical reaction ever, capturing the exchange of atoms by two molecules that had never been seen before.
Absolute zero is the lower limit of temperature in thermodynamic theory, which is about minus 273.15 degrees C. At that time, the molecules were largely stationary, resulting in no movement or heat at all. For the new study, the Harvard team cooled molecules to a temperature of only a few millionths of a millionth of the temperature in space — 500 nanometerkelin, which is lower than any natural occurrence in the universe. By contrast, in the coldest interstellar space, the average temperature is 3 Kelvin, or 3 billion nanokelines.
However, this is not the coldest natural environment – the record is still maintained by the Cold Atomics Laboratory on the International Space Station, where temperatures have dropped to 100 nanometerkelin.
In the Harvard study, researchers used gases containing potassium and thorium atoms. When these molecules collide, they exchange “partners”, which converts the potassium-thorium molecule into two molecules: one consisting of two potassium atoms and the other two gamma atoms.
Often, chemical reactions between molecules occur so fast that scientists can’t see everything – even the most sophisticated devices can only observe the disappearance of primitive molecules and the emergence of new molecules. The intermediate steps remain a mystery. But now, researchers have seen the missing link. At this super-cold temperature, chemical reactions occur at a rate of millions of a millionth of what is original, providing the team with a broader window into what happens.
When the potassium-seine molecule collides, the team was able to image for the first time a quad-atom molecule that was created briefly as an intermediate step. This allows the team to observe the breakof of atomic bonds and the formation of new atomic bonds. With this ability, the researchers say, they could study chemical reactions in more detail in the future. In addition to observation, the extended window allows scientists to intervene more precisely in chemical reactions, which could lead to a series of new applications. After all, chemical reactions are at the heart of pharmaceuticals, energy and household products.