Why is Oxygen a Nonmetal? (+ 3 Surprising Facts to Know)

Oxygen is a nonmetal because it lacks metallic properties such as luster, malleability, and ductility. It is also a highly electronegative element that tends to gain electrons to form negative ions. ¹

Well, this was just a simple answer. But there are few more things to know about this topic which will make your concept super clear.

So let’s dive right into it.

Explanation: Why is oxygen a nonmetal?

Oxygen is a nonmetal because it has several characteristic properties that distinguish it from metals.

Here are those properties:

• Poor conductor of heat and electricity: Oxygen is a poor conductor of heat and electricity, whereas metals are good conductors. This is because metals have free electrons that can move easily throughout the material, whereas oxygen does not have these free electrons. ²
• High electronegativity: Oxygen has a relatively high electronegativity, which means that it tends to attract electrons towards itself in a chemical bond. This is in contrast to metals, which have low electronegativity and tend to lose electrons to form positive ions. ³
• Tendency to form covalent bonds: Oxygen has a tendency to form covalent bonds with other nonmetals, rather than forming metallic bonds like metals do. Covalent bonds are formed by the sharing of electrons between atoms, while metallic bonds involve the delocalization of electrons over a lattice of metal ions. ⁴
• Physical state: Oxygen typically exists as a gas under standard conditions, whereas metals are usually solids or liquids. ⁵ This is because oxygen molecules have relatively weak intermolecular forces compared to the strong metallic bonds that hold metals together in their solid form.

All these properties collectively indicate that oxygen is a nonmetal.

Can oxygen form metallic bonds with other elements?

No, oxygen cannot form metallic bonds with other elements because it is non-metal. 

Metallic bonding occurs between metal atoms, where the outermost electrons of the metal atoms are delocalized and can move freely throughout the lattice structure, creating a “sea” of electrons that hold the metal atoms together. ⁶

Oxygen, on the other hand, has a strong tendency to gain electrons rather than lose them, and thus it forms covalent bonds with other non-metal elements or polar covalent bonds with more electronegative elements such as carbon and hydrogen.

Does oxygen show metallic properties?

Oxygen does not show metallic properties at normal conditions. But under some extreme conditions, such as very high pressures, it is possible for oxygen to exhibit some metallic properties. ^{7 8}

This phenomenon is known as “oxygen metallization” or “oxygen metalization”. When oxygen is subjected to extreme pressures, its electrons can become delocalized and start to behave like those of a metal, forming a metallic lattice structure. ^{9 10}

The transition from non-metallic to metallic behavior in oxygen occurs when the electrons in the outermost energy level of the oxygen atoms become so tightly bound that they are forced to overlap with the next energy level.

At this point, the oxygen atoms start to share their valence electrons with each other, leading to the formation of a metallic lattice structure. 

This lattice structure allows for the free movement of electrons and results in metallic properties such as electrical conductivity, thermal conductivity, and a metallic luster.

However, it’s important to note that these extreme conditions are not found under normal circumstances, and the phenomenon of oxygen metallization is not something that can be easily observed or harnessed for practical applications.

Further reading

Is Neon a Metal?
Is Sodium a Metal or Nonmetal?
Is Silicon a Metal or Nonmetal?
Is Phosphorus a Metal or Nonmetal?
Why is Sulfur a Nonmetal? 

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