Atoms are much too small to see with our eyes and even using a regular microscope won’t help. An atom is about a millionth of the thickness of a piece of paper or a human hair. That means if you line up a million atoms in a row, they’ll be as thick as a hair. Pretty small!
In 1981, the “scanning tunneling” microscope was invented. With this really powerful microscope we can actually see atoms. The scanning tunneling microscope has a very small, sharp tip that electricity is sent through. The scanner moves the tip across whatever is being looked at (called the sample). When the the scanner touches an atom, the electric flow changes. A computer that’s part of the microscope shows this change in current. Then it collects the information from different parts of the sample. In this way, the computer can make a map of electricity that shows where the atoms are.