Atom and Ion

This article will highlight the concept of Atom and Ion along with their differences. Tap to learn more.

What are Atoms?

The terms “atoms” and “element” are used interchangeably to refer to the basic building blocks of matter. In modern chemistry, chemistry is concerned with atoms and their structures. Atoms are considered as being the smallest parts of any substance. Typically no one knows how many atoms there are in a given chemical element.

Features of Atoms

The mass of an atom is very small (even smaller than the mass of a proton)

An atom has a dense nucleus surrounded by a cloud of electrons

It is believed that atoms are not divisible

If the above principle were not true, you would cut an apple into atoms and then make the apple out of only atoms

Ions are also another subatomic particle but with a different charge to mass ratio than a normal atom, it is believed that an electron has been detached from it, or conversely, an extra electron has joined it

What are Ions?

Ions may be defined as electrically charged atoms or molecules or ionic compounds (electrically charged compounds). Why do they have ions? Because they are composed of nuclei, electrons and free protons (atomic number = 1). In other words, an atom has a single proton layer surrounding it, but each ion carries a different number of these protons.

Features of Ions

Ions may be positive or negative, that is, they have a net electric charge

In general, the electrons of an ion are held more strongly by the nucleus than those of a neutral atom

Therefore, when an electron is ripped from its parent atom to become an ion and a free electron, it leaves behind a hole in the electron cloud (much like the hole in a donut) which then “pulls” another nearby electron away to fill it up (or even more than one)

The Opposites Attract

When the oppositely charged ions get together, they attract each other and form a bond because opposite charges attract. In other words, positive and negative ions attract each other. If a positive ion is surrounded by a neutral atom, it will deflate its electron cloud to become a new neutral atom (or the old proton from the original atom gets transferred to another nearby atom or molecule). This happens when they are in close proximity.

The strong attraction between opposite charges leads to ionic compounds being solid. Many substances on earth are ionic. Even water is made of two hydrogen atoms bonded together by an exchange of electrons to become H2O (water). However, when an ionic compound loses electrons (via reaction with oxygen or other gas molecules), it becomes electrically neutral.

Atoms and Ions: Difference

Atoms are the building blocks of all matter whereas an ion is a charged atom, i.e. an atom which has lost or gained one or more electrons in it (in which case it carries net positive or negative charge respectively).

The number of protons in atoms is equal to the number of electrons, but for ions the number of protons and electrons may not be equal.

Generally, atoms are neutral in charge whereas ions may be either positive or negative depending upon their charges.

A neutral atom will be surrounded by a cloud of electrons which forms its outer cover but an ion carries either more than one proton layer (“monatomic ion”) or less than one proton layer (“polyatomic ion”).

If a monatomic ion is surrounded by a neutral atom, it will deflate its electron cloud to become a new neutral atom (or the old proton from the original atom gets transferred to another nearby atom or molecule).

If an ionic compound loses electrons (via reaction with oxygen or other gas molecules), it becomes electrically neutral.

Atoms are considered as the smallest parts of any substance whereas ions are treated as electrically charged atoms.

Atoms are identical and serve as building blocks of all things whereas ions have different properties due to their charges.

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Conclusion

In nutshell, atoms and ions are two subatomic particles having distinct properties. They are two different types of particles which do not only differ in the mass but also in the charge and size. Their different properties make them quite different from each other, however their similarity makes them capable of combining with each other to form molecules and larger compounds.