The term atom has been derived from the Greek word ‘atomos’ which implies a substance which cannot be split or divided (Povh, 1999). A Greek scientist by the name Leucippe Milet was the first one to develop the idea way back in 420 B.C. Later on, one of his students expounded that matter was composed of tiny parts which were in continuous state of motion. Some of the general conclusions made included the fact that the atom cannot be seen because it is too small and that the free movement of these particles is only possible due to the availability of free space around the particle (Avison, 1989).
Further discoveries which have been made and confirmed about an atom has led to thorough understanding of its nature. For instance, matter exists in three states namely solid, liquid and gas. These three states further constitute what is known as an element, which is defined as a pure substance that cannot be separated into any other simpler form. This smallest part of an element is what is referred to as an atom.
The structure of an atom consists of three parts namely protons, electrons and neutrons (Povh, 1999). Both protons and neutrons are positioned at the centre of an atom better known as the nucleus while electrons are found on the outer levels of the atom or along the energy levels which are sometimes referred to as shells. While neutrons have no charge, protons have a positive charge and electrons are negatively charged.
Moreover, both protons and neutrons are static in position as they are permanently located at the nucleus of the atom while electrons are said to be delocalized owing to the fact that they move throughout the atom in an orbit through the energy levels (Avison, 1989).
The nucleus of an atom also constitutes the mass number of that particular atom. This mass is accounted for by the sum of protons and neutrons found at the nucleus.
An isotope is the term used to describe atoms of elements which have the same atomic number but different proton numbers hence different mass numbers. For example, there are two isotopes of carbon; Carbon-12 and Carbon-13.
Atoms can also secure charges. For instance, an atom which has been charged is known as an ion (Avison, 1989). Furthermore, negatively charged atom is called an anion while a positively charged atom is termed as a cation.
When there is an extremely high number of neutrons and protons in the nucleus, the atom loses stability and can then develop into a radioisotope.
Importance of atoms
From the outset, it is well understood that atoms form the basic part of life because they are the building blocks of any visible or invisible matter (Povh, 1999). The absence of atoms would imply the absence of nature itself because it is from the atoms that matter exists.
Applications of atoms
There are varied uses of atoms in day to day life. Apart from the reality that atoms are the building blocks of nature, there are other outstanding uses they can be put into. One such application is in the generation of nuclear energy. Atoms which have higher numbers of protons and neutrons usually have unstable nuclides which when bombarded with a high energy proton, can release enormous amounts of nuclear energy and which can be used to generate electricity or as process energy in industrial plants (Avison, 1989). Both nuclear fission and nuclear fusion processes are used in generating energy from atoms whose nuclei are unstable.
In summing up this paper, it is imperative to note that an atom is the smallest part of an element and it is the basic building block as far as matter is concerned. The centre of an atom (nucleus) constitutes of protons and neutrons and can be made use of in the production of nuclear energy especially if it is unstable. Electrons possess a negative charge and they are said to be delocalized because they continually move around the nucleus in orbits.
Avison, J. (1989). The World of Physics, London: Thomas Nelson & Sons Ltd.
Povh, B. (1999). Particles and nuclei: an introduction to the physical concepts, Berlin: Springer.