Which microscope is used for imaging surfaces at the atomic level?

The scanning tunneling microscope (STM) is the correct choice for imaging surfaces at the atomic level because it operates based on the principles of quantum mechanics. The STM uses a sharp conductive tip that is brought very close to the surface of a conductive material. By applying a voltage between the tip and the surface, the microscope can measure the tunneling current that occurs due to electrons moving from the tip to the surface—this current is highly sensitive to the distance between the tip and the atoms, allowing the STM to achieve atomic resolution.

In addition to providing topographical images of surfaces at an atomic scale, the STM can also probe the electronic properties of materials. This capability makes it extremely valuable for nanotechnology applications, including the study of surface defects, electronic states, and molecular arrangements.

Other types of microscopes, such as transmission electron microscopes and atomic force microscopes, while also powerful tools for imaging, have different modalities. The transmission electron microscope primarily transmits electrons through a sample and is better suited for visualizing internal structures at the nanoscale. The atomic force microscope uses a cantilever with a sharp tip to scan the surface and can achieve high resolution but is typically utilized for surface profiling rather than strictly atomic-level imaging. Optical microscopes, on the