For a long time, scientists believed they understood what happens when water meets air. This was also a common textbook topic. However, new water molecule discovery shows this understanding was incorrect.
A team of researchers has now discovered that the molecules at the surface of salt water behave differently than previously thought.
This discovery, led by Dr. Yair Litman from the Yusuf Hamied Department of Chemistry, challenges old beliefs in climate science.
The discovery goes beyond a simple science experiment. It has practical implications, particularly in improving our knowledge of how the atmosphere operates. This could be crucial in finding ways to lessen human impact on the environment.
The surface of water, such as in oceans or salt water, is where important chemical reactions happen. These reactions affect things like weather, climate, and even the air we breathe.
Scientists have long been unsure about how tiny charged particles in salt (called ions) behave at the surface where water meets air. Do they line up? Do they interact with water molecules in a specific way? Until now, scientists were mostly led by hunches.
Challenging textbook views on water molecules
The traditional textbook belief has been that ions, either positive or negative, would line up at the surface of water and arrange water molecules in one direction. However, new research shows this is actually not how molecules at the surface of salt water organize themselves.
Scientists used an improved technique called vibrational sum-frequency generation (VSFG) to study water molecules. In the past, this method helped observe vibrations at the surface, but it couldn’t show whether these vibrations were positive or negative.
This made it hard to fully understand. It was like trying to follow a conversation while only hearing half of it.
Water molecule discovery will force textbooks to be rewritten. Their discovery challenges decades of assumptions about water and ions, and it opens the door to a whole new area of research. This discovery about water molecules at interfaces represents a paradigm shift in… pic.twitter.com/BbAj62EE5J
— Nirmata (@En_formare) September 20, 2024
The findings showed something surprising. Ions on the surface of salt water don’t form a single layer and arrange water molecules in a singular way. Instead, they influence the water molecules in both upward and downward directions. This overturns earlier beliefs found in textbooks.
Dr. Litman explained that the surface of salt water is more complex than previously thought. The top few layers are pure water, followed by a layer rich in ions, and then the bulk of the salt solution. This discovery means the water molecules don’t line up neatly.
You might wonder why ion behavior at the water’s surface matters. The reason is that it plays an important role in understanding our atmosphere.
At the surface of water, especially in oceans, many important processes take place. These include evaporation, cloud formation, and how pollutants break down.
Without knowing exactly how ions behave at the water’s surface, scientists can’t make accurate climate models.