What's inside an Atom?

Atom has been the most fascinating thing in science. Atoms constitute everything we see around us. The walls, books, glasses, plates even your furniture is made up of atoms. What's amazing is that even we humans are made up of atoms. Some centuries ago, atoms were considered as invisible particles meaning that cannot be further classified. John Dalton, the scientist who founded atoms created a theory that the matter around us is made up of invisible particles Atoms which came from the word A-tomio meaning indivisible.

After further research and experimentation, scientists found out that the atoms contained negatively charged particles which was named electrons. This was a result of J.J Thompson's experiment on cathode rays. After few years, it was further known that atoms also contained protons and neutrons inside the it. This was a result of Ernest Rutherford and James Chadwick experiments on canal rays and alpha particles. Ernest Rutherford with his experiment on bombarding gold foil with alpha particles( positively charged radiations) predicted that the nucleus which contained the protons and neutrons were packed up in a extremely small size of 10⁻¹⁵m! This is so small which can be imagined that if the nucleus was of the size of a tennis ball then the whole atom of be as large as 5km! Through the gold foil experiment, it was also predicted that electrons revolved around the nucleus in orbits. This theory was later discarded due to its drawbacks in explaining the de-stability of the atom. Today, quantum theory of atom is used where electrons revolved around the nucleus in orbitals.

So what's inside protons and neutrons? Protons and neutrons consist of quarks which are one of the most basic forms of matter that make up the heavier elementary particles. There's also another theory which states that quarks also can be further divided into strings which form the basis of string theory. It predicts that everything in the universe is made up of strings and these strings vibrate at a certain fixed frequency to produce a certain form of matter. This means that each element and form of matter would have an unique string vibration frequency. Quite fascinating isn't it?