Structure of an Atom

During our school days, we all studied in science that atoms are made up of 3 particles – electrons, protons, and neutrons. The arrangement of electrons and protons are different in different elements. We also learnt that electrons are negatively charged (-) and revolve around the nucleus of the atom in concentric paths called orbits. Protons are positively charged particles (+). Neutrons are neutral or uncharged. Both these particles are tightly bound together within the atoms nucleus.

Now the real magic starts here. The number of electrons and protons are same in any atom thus making it neutral or uncharged. The number of protons present in an atom specifies its atomic number. The corresponding numbers of electrons are arranged in different elliptical orbits, called shells, around the nucleus. These electrons can rotate around the nucleus in all directions.

The electrons closest to the orbit possess huge force of attraction while the electrons in the farthest orbit have week force of attraction. These electrons in the farthest orbit are loosely held to the nucleus are called valence electrons and therefore rotate around the valence shell. Example – Copper has one valence electron.

Atomic Structure of Copper

Atomic Structure of Copper

Now the loosely held electrons in the outer shell / orbit often break free because of several reasons such as friction or collision. These “free electrons” randomly move around the space in between the orbits of the other atoms. Now the atom from which the free electron broke away is left with excess protons. And we know that the number of electrons and protons in an atom must be same for the atom to stay electrically neutral. But there are excess protons and lesser electrons. This makes the atom positively charged. Similarly, the free electrons can attach themselves to the valence shell of another atom thus making it negatively charged because there are excess electrons and we know electrons are negatively charged.

Example: Lighting in Sky during Thunderstorm. It is called Static Electricity.

Unit of Charge

The unit of charge is the Coulomb, C. The symbol of electric charge is Q.

Columb Formula

Columb Formula

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One Response to Structure of an Atom

  1.' lalit sharma says:

    very informative article..

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