Isomeric shift

An isomeric shift is like when you have two identical things, but one of them is hiding something special inside. It’s like when you and your friend both have the same toy car, but yours has a secret button that makes it go faster. Just like that, in science, two atoms of the same kind may have different abilities to act in a magnetic field, even though they're made of the same stuff. So, we call one of them an "isotope" and we measure the difference between the two using a fancy tool called a Mössbauer spectrometer. This helps scientists study tiny things that are too small to see with our eyes, like the atoms inside objects.