Class 10 Chemistry Chapter 3 Notes

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Class 10 Chemistry Chapter 3 Notes Pdf

Cbse Class 10 Chemistry Chapter 3 Notes Pdf

What are Metals and Non-metals?

Continuing the chapter 1 in Class 9th, i.e. Matter in our surroundings, this chapter focuses on the study of the classification of matter as well as metals and non-metals. The basis of the classification of metals and non-metals are the physical and chemical properties of elements. Let’s understand these physical and chemical properties as described in Metals and Non-Metals chapter in Class 10 Science:

Physical Properties of Metals & Non-Metals

First and foremost, we begin the classification, by comparing the appearance and scientifically called the physical properties of the elements. The different characteristics are due to the different structures of molecules that form the entire material. The physical properties given in the Class 10 chapter on Metals and Non-metals are:

Metals

Take a look at the physical properties of Metals:

Lustre: Metals possess a unique characteristic that makes their surfaces shining bright, in the pure state. This property of metals is called metallic lustre that makes the surfaces of iron, aluminium, and copper shine when rubbed with sandpaper.

Hardness: Metals are hard due to the tight packing of atoms close to each other in the crystal structure. This property of metals is called hardness which allows iron and copper to retain their shape and not get cut by a knife.

Malleability: Metals, when hit by a hammer multiple times, change their shape, and form sheet-like shapes. This property of metals is called Malleability that allows copper to be beaten into sheets.

Ductility: Metals are used in wiring different electrical appliances and also in the home electrical system. The Class 10 chapter on Metals and Non-metals also elucidates that this property which makes any metal attracted to wires is referred to as ductility.

Conductivity: Metals are used in the electrical system due to their property of conduction, which allows heat and electricity to pass through them. This characteristic of conductivity varies as per the number of electrons present in the last shell as they transport the electrical energy and thus determine conductivity.

Non-metals

While studying the Class 10 notes on Metals and Non-metals, you must also go through the following physical properties of Non-metals. This can be understood by different experiments between metals and non-metals to understand whether physical properties differentiate them from each other. Here are some examples to help you comprehend the same:

Mercury is the only metal which does not remain solid at room temperature.

As a non-metal, Iodine is lustrous which is a physical property of metals.

Carbon as a non-metal can be present in varied forms and its forms are referred to as allotrope such as diamond which is the hardest natural substance and has a higher melting as well as boiling point.

Graphite, as an allotrope of Carbon, is actually a conductor of electricity.

Alkali Metals are also soft in texture and can be easily cut with a knife.

Thus, through this comparison, it can be concluded that non-metals have varied forms and don’t have particular shapes unless it’s Iodine and Carbon. The chapter on Metals and Non-metals in Class 10 also highlights that a clearer difference between Metals and Non-metals can be presented through their varied chemical properties.

Chemical Properties of Metals and Non-Metals

The chemical properties of metals and non-metals can be explained through the analyses of the reactions of metals with distinct elements. The following sections elucidate the major reactivity experiments conducted in the chapter on Metals and Non-metals in Class 10:

Reactions of Metals when Burnt in Air

Metals burn in oxygen to form different compounds of metal and oxygen. As per the chapter on Metals and Non-metals in Class 10, metals combine with oxygen to form metal oxide.

The metal oxides formed are insoluble in water, but some dissolve in water to form alkalis.

Reactions of Metals with Water

While going through the chapter on Metals and Non-metals in Class 10, you will get to explore the reactivity of metals with water. Metals react with H2O to form a metal oxide, releasing hydrogen gas.

Metal+ Water→Metal oxide + Hydrogen

Example:

2K(s) + 2H2O(l) → 2KOH(aq) + H2(g) + heat energy

2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g) + heat energy

2Al(s) + 3H2O(g) → Al2O3(s) + 3H2(g)

3Fe(s) + 4H2O(g) → Fe3O4(s) + 4H2(g)

Reaction with Acids

Metals react with the acid to give salt and hydrogen gas.

Metal + Dilute acid → Salt + Hydrogen

While studying the chapter on Metals and Non-metals in Class 10 Science, you must also remember that not all the metals react with acids. Some, like copper, don’t react with dilute HCl.

Reactions of Metals with the Solution of Other Salts

When metals react with a solution of another metal salt, the more reactive metal easily displaces the less reactive element from the solution. Take a look at how this reaction works as elaborated in Metals and Non-metals in Class 10:

Metal A + Salt solution of B → Salt solution of A + Metal B

In the above reaction, metal A is more reactive than metal B.