Yes, a scanning tunneling microscope (STM) allows scientists to observe individual atoms and molecules at the atomic scale. Unlike optical microscopes, which use visible light to magnify and resolve objects, an STM operates based on the principles of quantum mechanics.
In an STM, a sharp probe with a single atom at its tip is brought very close to the surface of a sample. A small bias voltage is applied between the probe and the sample, creating a tunneling current. The magnitude of this current is highly sensitive to the distance between the probe and the surface. By maintaining a constant current, the STM can precisely control the height of the probe above the surface, effectively scanning the surface atom by atom.
The resulting data is then used to generate a topographic map of the sample surface, where variations in height are represented as peaks and valleys. These maps reveal the positions of individual atoms, allowing scientists to visualize the atomic arrangement and study surface properties with incredible resolution.
However, it's important to note that the images produced by an STM do not resemble conventional optical images of beads or spheres. Instead, they typically appear as a series of bumps or depressions representing the positions of atoms on the surface. The STM provides a unique and direct insight into the atomic structure and properties of materials, enabling scientists to study and manipulate matter at the atomic scale.