Ions and Ion Formation Study Guide

Any atom or group of atoms with one or more positive or negative electrical charges is called an ion.


Look at the image shown below. Do you know that all of those items have something in common? They are all made up of ions! What are these ions? Let’s find out!

Examples-of-Ionic-Compounds Source

What are IONS?

Ions are generated when electrons are added to, or removed from, neutral atoms (containing the same number of protons as electrons), molecules, or other ions.

They are also formed when ions combine with other particles; or when a covalent connection between two atoms is ruptured, leaving both of the bond's electrons associated with one of the formerly connected atoms. Now that we have learned what ions are, let’s discuss how they are formed.

Ions transfer Source


Ionization is the phenomenon of a neutral atom shedding or acquiring electrons, resulting in ions' formation. Ions are formed when the number of protons in an atom does not equal the number of electrons. An ion therefore is an atom that has gained or lost one or more electrons and therefore has a negative or positive charge.

Ionization is the process of exchanging electrons among atoms or molecules. The procedure is motivated by the desire to obtain more stable electronic configurations, such as the octet rule, which stipulates that the outermost (valence) shell of most stable atoms and ions has eight electrons.

If an atom or molecule gains an electron, it becomes negatively charged (an anion), and if it loses an electron, it becomes positively charged (a cation).

Sodium (Na) is a prominent example of an ion. Because sodium possesses eleven electrons, it has a positive charge. On the other hand, Sodium would be more stable with 10 electrons, according to the octet rule (2 in its innermost shell, 8 in its outermost shell). As a result, sodium loses one electron to become much more stable.

Electron Transfer Source


Ions, especially as gases, are extremely reactive. They normally generate neutral compounds when they interact with ions of the opposite charge. The same-charged ions repel each other. A magnetic field may also deflect ions, as shown in the first photograph of the northern lights.

If an atom or molecule gains an electron, it becomes negatively charged (an anion), and if it loses an electron, it becomes positively charged (a cation).


  • Atoms may receive or lose electrons and therefore become ions, atoms with an uneven number of protons and electrons and hence have a positive or negative charge.
  • Ionization is the transformation of an atom into an ion.
  • Ions are reactive particles attracted or repelled by other charged particles and are diverted by a magnetic field.


1. What is the purpose of ion formation?

When atoms lose or gain electrons to meet the octet rule and have entire outer valence electron shells, ions are created.

2. What is the rule for forming ions?

Metal atoms drop their highest energy level electron, or electrons, and produce positively charged ions. Nonmetal atoms gain one electron or multiple electrons to form negatively charged ions.

3. Why is knowing about ions important?

Body fluid contains electrolytes, which form charged ions when dissolved in water. These ions allow electrical messages to flow freely throughout the body. Electrolytes perform a critical role in the body, regulating osmotic pressure in cells and assisting muscle and nerve cell activity.

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  1. Ions. Accessed 26 Jan 2022.
  2. Formation of ions. Accessed 26 Jan 2022.
  3. Properties of ions. Accessed 26 Jan 2022.