Structure Of Atoms

Atoms are chemically the smallest building block of all the elements in nature. We cannot imagine our existence without the existence of atoms that form and shape us and every single thing present around us. There have been multiple theories and models that scientists have proposed to explain electrical neutrality and the existence of subatomic particles. Many scientists have also tried to explain the structure of atom. 

Atom

The simplest way to understand an atom is to think of the atom as the building block of every element that occurs on earth. Just like the human body is made up of cells, elements, compounds, and everything on earth is composed of atoms. All the atoms that exist in nature are identical in shape and size, and the diameter of each of these atoms is said to be equal to 2-3 Å. 

Structure of atom

When we break an atom into smaller subatomic particles, we get protons, electrons and neutrons as the final product. These subatomic particles are the reason behind the determination of the mass and charge of the atom.

When various atoms combine with one another, they lead to the formation of elements that further combine to form gases, liquids or solids. 

We can understand this with an example. Ammonia is formed by combining 1 Atom of Nitrogen and 3 atoms of Hydrogen. Chemical reactions in nature are run to break the existing atomic bond and then form a better and more useful output. 

The atomic structure can be understood by visualising a central mass where the atom’s positive charge is concentrated. Here you will find the protons and the neutrons. However, hydrogen is the only atom where you may come across only one proton and one electron. Neutrons are absent inside the nucleus of hydrogen. 

Now, to maintain the electrical neutrality of an atom, the addition of a negative charge is important. Hence, electrons are present outside the nucleus in their electron shells. 

The number and arrangement of these basic parts of an atom determine the existence of many other basic particles. 

Atomic number and mass number

An atomic number is the total of all the protons present inside an atom. On the other hand, the mass number is defined by the total of both the neutrons and the protons. In a neutral atom, the number of neutrons and protons is equal. However, a variation in the number of neutrons may result in the formation and existence of isotopes. Isotopes are a form of the same atom, and the only difference arises in the number of neutrons that each of these atoms possesses. For elements that have isotopes, the mass number is calculated by taking an average of the mass of isotopes. 

Discovery of electrons and protons

J.J. Thomson is credited for the discovery of electrons as subatomic particles. According to him, these electrons revolve in their respective shells around the nucleus. 

After Thomson, Rutherford is credited for discovering and finding a positively charged particle, i.e. The proton. 

Sir James Chadwick is credited for discovering the neutral particles, i.e. the neutrons. Since neutrons do not have any charge, determining their exact location is tedious. 

Another surprising fact that people may have analysed is that neutrons and protons can further be broken down into quarks. These quarks can be of 6 different types. 

Conclusion

Atoms are considered the building blocks of all the major things that exist in nature. When we try breaking down an atom into smaller particles, we come across protons, Neutrons and electrons, later termed the subatomic particles. 

Atomic structure is a complex structure, and its study has proved important for the discovery of many things which would have otherwise remained undiscovered. Further studies are still in progress, and a day may come when we may also come across smaller units than electrons, protons and neutrons.