Metals and Non-Metals are two important classes of elements. Metals are those elements that are present on the left side of the periodic table and contain 1, 2 or 3 electrons in their valence shell. Non-metals on the other hand are the elements that are found on the right side of the periodic table and contain 4, 5, 6 or 7 electrons in their valence shell. In this article, we will see the exact difference between metals and non-metals.
Metals are hard and contain metallic bonding while non-metals have covalent bonding between the atoms and they can be in solid, liquid, or gaseous form. Nonmetals are usually soft. Metals and non-metals can be differentiated on the basis of their properties.
There are 118 elements discovered so far, out of which nearly 95 are metals. So a vast variety of elements is covered by metals in the periodic table. Metals are further classified as Alkali Metals, Alkaline Earth Metals, transition metals, post-transition, or basic metals, lanthanides, and actinides.
Metals vs Non-metals
Let’s see the differences between metals and non-metals through the following table.
| Basics | Metals | Non-metals |
| Electronic Configuration | Metals contain 1,2 or 3 electrons in the outermost shell of their atoms except for hydrogen. | Non-metals have 4,5,6 or 7 electrons in the outermost shell of their atoms. |
| Conductivity | Metals are good conductors of heat and electricity. | Non-metals are poor conductors of heat and electricity. Graphite is an exception which is a good conductor of electricity. |
| State | Metals are generally solids at room temperature except for mercury which is a liquid at room temperature. | They can be solid, liquid, or gas at room temperature. |
| Malleability | Metals are malleable which means they can be beaten into sheets. | They are non-malleable and brittle. |
| Ductility | Metals are ductile i.e. they can be drawn into wires. | They are non-ductile. |
| Luster | Metals are lustrous (shiny) as they have the property of reflecting light from their surfaces. | They don’t possess luster. |
| Tensile Strength | Metals have high tensile strength due to the high molecular force of attraction between their molecules. | Non-metals possess low tensile strength because of the low molecular force of attraction. |
| Density | They have quite high density. | They have low density. |
| Melting and boiling point | The boiling and melting point of metals is quite high. | They have low melting and boiling point. |
What are metals?
The electropositive elements found on the left side of the periodic table in which the atoms are bound together by the metallic bonds are known as Metals. These are hard substances and are good conductors of heat and electricity. They possess shiny nature. This is because they possess free electrons which vibrate in the presence of light and appear as a shiny surface. However, lead is an exception that possesses a dull appearance.
Most of the elements found in the periodic table are metals. Therefore they are further subdivided into Alkali metals, Alkaline Earth metals, basic metals, transition metals, post-transition metals, lanthanides, and actinides.
Since metals have 1, 2 or 3 electrons in their valence shell, they can easily form cations by losing these electrons and thus can acquire stability. Because elements having 8 electrons in their valence shell acquire stability. Metals react with acid and release hydrogen gas.
Generally, metals are hard and solid while mercury is an exception which is a liquid at room temperature. Metals like Sodium and Potassium are also not hard so they can be cut down with the help of a knife without exerting much force.
What are Non-metals?
Elements having 4, 5, 6 or 7 electrons in their valence shell and tend to form anions by gaining electrons during a chemical reaction are known as Non-metals. These elements are electronegative. They are poor conductors of heat and electricity. Graphite in spite of being a non-metal is a good conductor of electricity.
Non-metals possess low melting and boiling points. However, the melting point and boiling point of carbon and silicon are quite high. Non-metals are found in all three states of matter i.e. solid, liquid, and gas. But they are soft even in the solid-state so they get converted into powdered form even on the application of a small amount of force. However diamond is an exception which is the hardest substance known so far.
Non-metals are found on the right side of the periodic table. They include the non-metal, halogen group, and noble gases. They are not malleable and ductile like metals.
Conclusion
From the above discussion, we have concluded that metals and non-metals possess different properties. And they can be differentiated or distinguished on the basis of these properties. There is also the third class of elements in the periodic table which is neither metals nor nonmetals known as metalloids. It is important to know the differences in properties between metals and non-metals to identify a metalloid because it possesses some of the properties of metals and other non-metals. Metalloids are present at the center of the periodic table.
Author
Deepak Yadav
Aligarh Muslim University, Aligarh
