Atoms

Atoms

An atom is the smallest particle of an element which can take part in a chemical reaction. It can also be defined as the smallest part of an element that can exist alone or can combine with substances to form a molecule.

The ancient greeks were the first to use the word atom which is invincible, to describe the smallest particle of any substance. It's actual existence was not established until the nineteenth century when particle of any substance. John Dalton, an english chemist, put forward the theory to describe the nature of the atom.

Dalton's atomic theory

In 1818, John Dalton propose the atomic theory which can be summaries as follows:

• All element are neither are made up of small, indivisible particles called atoms.
• Atoms can neither be created nor destroy.
• Atoms of the same elements are alike in every aspect and differ from atoms of all other elements.
• When atoms combine with other atoms they do so in simple ratio.
• All chemical changes result from the combination or the separation of atoms.

Modification of dalton's atomic theory

Dalton's atomic theory could not explain electrolysis ans some other phenomenum and some of the basis assumption are later prove to be wrong. This discoveries have given rise to modification of the theory and the modern atomic theory of matters now as follows:

• All matter are made up of small particles some of which are positively charge (Protons), some are negatively charged (electrons), while some are electrically neutral (neutron).
• The atom of the same element are not all alike but may have different masses as prove by the phenomenom of isotophy.
• Atoms of different elements can be combined together to form molecules.
• An atom can be destroyed and created when redioactive atoms are produced.