Tetrafluoroammonium is a long word that describes a tiny, tiny thing called a molecule. A molecule is like a really small team of atoms that work together to make something new.
This molecule is made up of four atoms of fluorine and one atom of nitrogen. Fluorine is a chemical element that is really good at making things not stick together or dissolve. Nitrogen is another element that is really important for living things to grow.
This molecule is special because it is really good at dissolving other things that don't usually dissolve in water, like salts. It's like a superhero that can break up bad guys and make them go away.
But, even though it's great at dissolving things, it is also really dangerous if you touch it or breathe it in. That's why it needs to be handled very carefully by scientists who wear special gloves and masks to keep themselves safe.
So, even though tetrafluoroammonium is a big word, it really just means a tiny, powerful molecule that scientists use to help them with their studies.