Atoms are the smallest unit of matter before matter starts getting weird.
Atoms typically behave in predictable ways to maintain stability, and on the surface, they fit intuitive and logical notions that do not challenge human understanding about the nature of reality, but when scientists began to peel back the surface, they found Alice’s rabbit hole. Inside the atom lies, a teeny tiny nucleus of protons and neutrons, an electron, and, between them, a vast expanse of empty space. Everything that is, mostly isn’t. All things are mostly nothing. Crazy, isn’t it? Unbelievable!
How empty is it, and if atoms are empty, why does matter seem solid?
Atoms are small, smaller than humans can realistically imagine (unless you can imagine something a 10 billion times smaller than a meter, i.e. 100 picometers), so it useful to imagine them as larger to understand how empty they are. In a typical atom, the radius of the nucleus is 20,000 times smaller than the radius of the atom. In some atoms, it can be 100,000 times smaller. That means if the atom were as large as the earth with a radius of approximately 6400 kilometers (4000 miles) and the nucluer radius is 20,000 times smaller, the radius of the nucleus would be less than 1/3 kilometer (1/5 mile). All the rest of the earth would just be space for the electron, which is odd given that, near as anyone can tell, electrons have no volume.
How can anyone reconcile this empty notion given matter’s apparent solidness? It’s easier when one considers the fact that electrons are extremely fast. They are almost impossibly fast at a speed approaching 300,000 kilometers/sec (186,000 miles/sec). If they were one iota faster, they would literally be impossibly fast. At that speed, an electron can travel the circumference of the earth seven times in one second. Imagine how many times it can travel around a space that’s submicroscopic (note: electrons do not orbit a nucleus like a planet orbits the sun). Electrons are virtually everywhere at once within their atoms radius. The fact that electrons are everywhere at once makes matter solid. At least sort of; its actually more complicated than that. There are other factoids about subatomic particles like electron repulsion and the pauli exclusion principle that also make atoms more than mostly empty space.
Stay tuned for definitions of electron orbitals, energy shells and their relation to biology.
-Loup Mal
Biotranslation 