An atom is a fundamental building block of matter. We see a picture of the atom in books and you might have drawn an atom during your school years. Does an atom look just round like that?

The Actual Picture of an Atom
Photo by Hal Gatewood on Unsplash

The Actual Picture Of an Atom

We are a being who wants to visualize everything. We want to see light in terms of rays or even abstract quantities like love in terms of behaviors. Maybe visualization assures the existence of something in my view. Yes, the very essence of the existence of something is its visualization.

This is why the concepts of atoms were discarded until Albert Einstein let people visualize atoms by statistical interpretation of Brownian motion. Viola! There is an atom, it exists mathematically. But, the actual picture of the atom remained obscure because of its miniature nature. Now, things are different.

What Does an Atom Look Like?

Atoms are things that make up every matter. So, in a sense, you do see atoms. It’s what everything is, you are also a lump of atoms, aren’t you? But have you wondered about the picture of the atom, an individual one?

An atom’s size is about 10-100 billionth fraction of a meter. So, visualizing an individual atom is a somewhat difficult task, not impossible as modern technology has insinuated. Despite such miniature nature, the development of the electron microscope has now made scientists able to actually take pictures of an atom. You can find a picture of an atom, a single and isolated one here.

Atoms are point objects. A point on a paper is approximately circular and in three-dimensional space is a sphere. So, in a sense, it is customary to think of an atom as spherical.

Also, if you have a very high-resolution microscope, which can distinguish an object separated by nearly hundreds of millionth fraction of a meter, you can just see a dot, a sphere. Maybe in the future, we will be able to see it in much greater detail, but for now, it’s just spherical. The better picture of an atom is a mathematical one.

Is Atom a Perfect Sphere Then?

The picture we have taken till now shows they are spherical. Even from the beginning of school level, we were taught that atoms are spherical, every demonstration contained spherical billiard ball-like objects as atoms. But, is this spherical picture correct?

In certain approximations, this picture of the atom is correct. There can be distortions and we may ignore them for making things easy. The clouds of electrons revolving around a potential set up by a nucleus with a certain discrete energy, give us a spherical view.

Hurdles in Visualization

The size of an atom is extremely small. So, there are various difficulties in picturing it. Ordinary visible light has a wavelength far greater than atomic size, so it cannot be used to see atoms. Such light can be diffracted and a clear image is not formed. However, electrons can have wavelengths 100,000 times smaller than visible light, so they can have better resolving power.

An electron microscope also can be used to see atoms but still, it has limited resolution. We can see just the spherical picture of an atom as we discussed above. And, a microscope having better resolution than an electron microscope has yet not been developed yet.

The size of the atomic world is not just the reason that makes it difficult to visualize, its weirdness makes things even more complex. The electrons in an atom behave as a wave as well as a particle and there is uncertainty, the Heisenberg’s uncertainty. So, seeing atoms as we see objects in real life is completely absurd. There is only one true picture of the atom and its mathematical picture.

The Actual Picture of an Atom

Atoms are actually invisible to us. Visible light, the light we see cannot resolve the image of an atom. So, the actual picture of an atom is mathematical. Mathematics is the only thing sensed by physicists and a mathematical picture is the true picture of the atom.

According to it, the electrons are around the nucleus, each in a fixed state, represented by a mathematical function called a wave function. Not just electrons, but all the quantum particles can be represented by a wave function. The wave function has all the information about the particle and if we want to measure any values associated with it, we use an operator associated with it.

Similarly, the particles in the nucleus, neutrons, and protons also can be represented by such state functions. Finally, the only thing we need is the mathematical value of different quantities that are associated with a particle, which can be obtained from those functions. If we can calculate them with greater accuracy, the resolution is greater. This is what a picture of an atom looks like, you just calculate, after all, seeing is also an act of measurement.

Ashwin Khadka is a PhD Scholar in Nano Energy and Thermofluid Lab in Korea University, Republic of Korea under Korean Government Scholarship Program. He has a Masters Degree in Physics from Tribhuvan University, Kathmandu, Nepal. He is a science enthusiast, researcher and writer.