How can we see atoms?

Answer 1

It is an interesting question!

Technically, you cannot "see" anything smaller than the shortest wavelength of light that you can see it with. The shortest wavelength violet light is 4 x 10-7 meters. An atom is about 10-11 meter. So an atom is 4 x 104 or 40,000 x too small to be seen.

But there are ways to "visualize" it, like Atomic Force Microscopy. But these are all just measurements converted to computer images, and are not in any real sense "seeing" the atom.

SpheresSee pictures of actual atoms! Click the Web Links to the left of this !

Atoms look like very very tiny spheres (or more like cones when on a surface), although there is no way to see this with an kind of optical microscope. However, there are imaging techniques, such as something called STM, or scanning tunneling microscopy, that allows you to see the shapes of atoms. The shape of the atom is determined only by the shape of the electron cloud surrounding it. Using STM, you can map out the shape of the electron cloud by using a metallic tip that interacts with the electrons in the atom, allowing you to see where they are. As the tip moves over the sample, a current, called a tunneling current, is passing from the atoms to the metallic tip. The amount of current is extremely sensitive to the distance from the atom to the tip. So, as you move the tip around over the atoms, you can map out the shape and size of atoms.

Another technique, but with lower resolution, is called AFM, for atomic force microscopy. This also uses a metallic tip, but instead of interacting with the electrons directly, it vibrates at a certain frequency, and when it approaches an atom, the frequency changes. If you monitor the frequency as you move the tip, you can map out the shape of atoms.

You can also see molecules using both these techniques. See the related links for more about STM, AFM, and some beautiful images of atoms taken at IBM Almaden using STM.

You can't see atoms in any normal sense of using an optical microscope. In fact, not even fancy electron beam microscopes have that capability.

You can however image atoms using a technique called STM or scanning tunneling microscopy. You don't get an optical image, but it does allow you to map out an image of the atoms of a molecule. To do this you use a metallic tip which interacts with the atoms you want to image. As you move the tip over the atoms, you pass a current, called a tunneling current, between the tip and the atom. This current is extremely sensitive to the distance between the atom and the tip. As you move the tip over the atom, you can map out what it looks like using the size of this tunneling current.

See the Web Links to the left of this for more information about STM and check out the beautiful pictures taking at IBM Almaden of atom in their picture gallery. Make sure to visit all the "rooms" in the gallery for some amazing images!

Answer 2

Atoms are so small that they cannot be viewed with an optical microscope, which operates between the wavelengths of 400 and 700 nanometers. Instead, individual atoms can be observed through the use of a scanning tunneling microscope, which has a lateral resolution of 0.1 nanometer.

Answer 3

STM -can visualize surface atoms and convert signals into a picture on a monitor No visual direct ways since it is smaller than the wavelength of light.

Answer 4

through single crystal x-ray studies