Metals and Non-metals
Physical Properties of Metals and Non-Metals
Do you know how many elements are there in our periodic table?
There are 118 elements in the modern periodic table. These elements can be broadly classified as metals and non-metals depending on their properties.
Elements that lose electrons to form compounds are called metals whereas elements that gain electrons to form compounds are called non-metals. Elements such as Si, Ge, As, Sb and Te show the characteristic properties of both metals and non-metals. They are called semi-metals or metalloids. Here, we will discuss metals and non-metals along with their physical properties in detail.
These elements are electropositive and contain less than or equal to three electrons in their valence shell. Metals such as aluminium, copper, and iron are widely used around us. Metals are used for the construction of bridges, automobiles, airplanes, ships, trains, etc. We will now discuss the physical properties of metals.
Physical properties of metals:
1. Metallic Lustre: The surface of most metals is shiny. The lustre associated with metals is known as metallic lustre. For example, iron, copper, gold, and silver are very shiny. Metals such as gold and silver are very lustrous. Therefore, they are used for making jewellery.
Silver is used for making mirrors because of its excellent shine and reflective nature.
Some metals do not look very lustrous. This is because they either lose their lustre or their lustre gets reduced when exposed to air for a long time. This happens due to the formation of a layer of oxide, carbonate, and sulphide on their surface. If a metal surface is rubbed with sand paper, then this layer gets removed and the shiny surface of the metal can be seen. The layer formed in some cases is stable and sticks on the surface of the metal, but in other cases, it is unstable and falls off (as in the case of rusting of iron).
2. Hardness: Metals are generally hard in nature. However, this hardness varies from metal to metal. Most metals such as iron, aluminium, etc. are very hard and cannot be cut with a knife whereas some metals such as sodium and potassium are very soft and can be cut using a knife.
3. Malleability: Metals are malleabl...
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