Metals and non-metals form two broad categories of elements, each with distinct properties and characteristics. Chapter 3 of CBSE Class 10 Science focuses on understanding these properties, their chemical reactions, and their applications. This blog will provide a concise overview of the key topics from this chapter to help students prepare efficiently for their exams.

Introduction to Metals and Non-Metals

Metals and non-metals are distinguished based on their physical and chemical properties.

• Metals are typically shiny, good conductors of heat and electricity, and possess high malleability and ductility.
• Non-metals, on the other hand, are generally dull, poor conductors of heat and electricity, and tend to be brittle in solid form.

Physical Properties of Metals

Metals possess several key physical properties:

• Malleability: Metals can be hammered into thin sheets without breaking.
• Ductility: They can be drawn into thin wires.
• Conductivity: Metals are excellent conductors of heat and electricity due to free-moving electrons.
• Luster: Metals have a shiny appearance because they reflect light.

Physical Properties of Non-Metals

Non-metals have contrasting properties to metals:

• Dull Appearance: Non-metals lack the shiny luster of metals.
• Poor Conductors: They do not conduct heat and electricity efficiently.
• Brittle: Non-metals are typically brittle in solid form and break easily.

Chemical Properties of Metals

Metals react with various substances to form compounds:

• Reaction with Oxygen: Metals form metal oxides when they react with oxygen. For example, magnesium reacts with oxygen to form magnesium oxide (MgO).
• Reaction with Water: Some metals like sodium react with water to form metal hydroxides and hydrogen gas.
• Reaction with Acids: Metals react with acids to form metal salts and release hydrogen gas. For instance, zinc reacts with hydrochloric acid to form zinc chloride (ZnCl₂) and hydrogen gas.

Reactivity Series

The reactivity series is a list of metals arranged in order of their reactivity. Highly reactive metals like potassium are placed at the top, while less reactive metals like gold and platinum are found at the bottom. This series helps predict the outcomes of displacement reactions and determines how metals react with other substances.

Extraction of Metals

The extraction of metals involves obtaining metals from their ores, often through processes like:

• Smelting: Heating ores with a reducing agent (like carbon) to extract the metal.
• Electrolysis: Using electric current to extract metals from their compounds.

Alloys

An alloy is a mixture of two or more elements, where at least one is a metal. Alloys have improved properties compared to pure metals. Examples include:

• Brass: A mixture of copper and zinc.
• Steel: A combination of iron and carbon.

Alloys are commonly used in construction, transportation, and manufacturing due to their enhanced strength and durability.

Corrosion and Its Prevention

Corrosion is the process of metal deterioration due to chemical reactions with substances like oxygen and water. For example, iron rusts when it reacts with water and oxygen to form iron oxide (rust).

To prevent corrosion:

• Galvanization: Coating metal with a layer of zinc.
• Painting: Applying a protective paint layer.
• Using corrosion-resistant alloys: Metals like stainless steel are resistant to corrosion due to their alloy composition.

Conclusion

Chapter 3, “Metals and Non-Metals,” covers the essential properties, reactions, and applications of these elements. Understanding the physical and chemical properties, as well as the reactivity series, helps students not only in exams but also in everyday applications of science. With these short notes, you are now equipped to revise the topic efficiently and score well in your exams.

Stay organized, keep revising, and make use of additional study resources like Physics Wallah notes for further clarification and practice. Best of luck with your preparations!

Also Read: Best Strategies for Better Exam Preparation with ToppersSky

Acids, bases, and salts are an important part of our daily life. The foods we consume, the cleaning components we use, and our bodies all comprise them. This chapter gives a well-known overview of these materials, their characteristics, and their importance in chemistry and daily life. 

Acids, Bases, and Salts Definitions

Acids: Acids are substances that turn blue litmus paper red and give it a sour taste. In water, they emit hydrogen ions (H⁺). Acetic acid and hydrochloric acid (HCl) are two examples.

Bases: Bases are substances that turn red litmus paper blue and have a soapy texture and a bitter taste. In water, they release hydroxide ions (OH⁻). Calcium hydroxide and sodium hydroxide (NaOH) are two examples.

Salts: Salts are substances that are created when bases and acids combine. They are usually neutral and include positive (from bases) and negative (from acids) ions. For example, take sodium chloride (NaCl).

Acids, Bases, and Salts Chemical Properties

Acids:

• Acids react with metals to produce hydrogen gas.
• Acids turn blue litmus paper red.
• Acids react with carbonates and bicarbonates to produce carbon dioxide gas.

Bases:

• Bases feel slippery and turn red litmus paper blue.
• They react with acids to form salt and water.
• Bases react with certain metals like zinc to produce hydrogen gas.

Reactions

Acids and Bases with Metals:

Acid and Base Reaction (Neutralization):

 

Similarities Between Acids and Bases

• Both acids and bases are electrolytes and can conduct electricity.
• Both react with metals (though bases react with fewer metals).
• Both react with each other to form salt and water.

pH Scale and Its Importance

The pH scale measures the acidity or alkalinity of a solution, starting from 0 (highly acidic) to 14 (highly basic), with 7 being neutral.

Importance of pH Scale in Daily Life:

• The pH of soil affects plant growth.
• pH balance in our body fluids is essential for health.
• pH is used in water quality testing and food preservation.

Common Compounds and Their Uses

Bleaching Powder Uses CaOCl2

• Used in disinfecting water.
• Acts as a bleaching agent in the textile and paper industries.

Baking Soda Uses NaHCO3 

• Used in baking as a leavening agent.
• Neutralizes acid in indigestion remedies.

Washing Soda Uses  (Na2CO3·10H2O)

• Used in cleaning agents.
• Removes the hardness of water.

Plaster of Paris Uses (CaSO4⋅12H2O)

• Used in making casts for broken bones.
• Employed in decorative designs and construction.

Conclusion

Acids, bases, and salts are essential to our expertise in chemistry and are used extensively in home, commercial, and agricultural settings. By understanding their characteristics and reactions, we can better understand nature and maximize its potential for useful purposes.

Also Check: How to Get 90+ Marks in Science Class 10th NCERT Exam

Introduction

This chapter is all about how chemical changes take place within a state of a matter. Different examples in nature remind us of physical and chemical changes that things undergo. For example, grapes getting fermented, milk kept at room temperature in summer, food getting cooked, etc. How do these things happen? What is the reason behind it? This chapter on chemical reactions and equations explains it all. This can be explored by means of general observation of how substances change.

A chemical reaction takes place when there is either a change of temperature, state, or color or there is an evolution of some gas. These observations tell us that a chemical reaction has taken place. Let us move forward and explore even more.

Chemical Equations

When two substances react, they form a new product. There is a change of state of the reactants and they give a new product in the reaction.

The left side of the arrow displays the substances that react, combined by a (+) sign, while the right side displays the product that is formed. The arrow gives the direction of the reaction.

Formulae notations represent a chemical equation.

Balanced Chemical Equations

In chemical reactions, laws of conservation of mass hold. That is the total mass before and after the reaction remains constant and does not change.

When more than one reactant is involved in a chemical reaction, one reactant oxidizes while the other reduces, causing oxidation and reduction to occur simultaneously. This process is known as a redox reaction.

Types of Chemical Reactions

1. Endothermic Reaction

When the heat is soaked up by the reactants from the environment it is called an endothermic reaction.

Example :

1. Melting ice cubes
2. Evaporating liquid water

 

2. Exothermic Reaction

Chemical reactions in which the heat moves from the internal environment to the external environment, that is heat is given out, are called exothermic reactions.

Example :

1. Combustion
2. Rain

Let us consider an experiment where the teacher gives two salts.  Ammonium nitrate (NH₄ NO₃) and calcium chloride (CaCl₂). The teacher asks to put these salts in water and observe the changes. We know that water and salt are in a flask. Let us consider the flask as the outer environment.

When we added ammonium nitrate, the reaction absorbed heat from the surroundings and made the flask cold. This indicates an endothermic reaction. While adding CaCl₂ , heat is released into the environment. This represents an exothermic reaction.

One method to learn this is exo-heat given to the external environment!

Oxidation and Reduction Reactions / Redox Reactions

When a reactant combines with oxygen, it is said to be oxidized and that is called oxidation. Whereas, when a reactant gives away the oxygen, it is said to be reduced and is called reduction.

Observers noted in the above reaction that copper loses oxygen and undergoes reduction, while hydrogen gains oxygen and undergoes oxidation.

Redox Reactions

In a chemical reaction involving more than one reactant, one reactant undergoes oxidation while the other undergoes reduction. This simultaneous process of oxidation and reduction is termed a redox reaction.

Effects of Oxidation and Reduction in Everyday Life

These scientific processes also affect daily life activities, for example

1. Corrosion:

Iron reacts with moisture present in the air and the oxygen, and gets rusted. This is called corrosion.

Similarly, when elements like silver and copper come into contact with moisture and oxygen, they undergo a color change, turning black and green respectively. This color change is also a result of corrosion.

2. Rancidity:

This process oxidizes food products containing fats and oil, resulting in a change in color and smell.

FAQ

1. What is the total number of marks the chapter has?
   This chapter comprises a total of six marks. It makes 7.5 %.
2. What are the important topics in this chapter?
   Some of the most important topics include Balancing the chemical equation, types of reactions, and the effect of oxidation reactions.
3. How can ToppersSky help in scoring full marks?
   You can complement your learning by watching toppersSky videos and can make the best use of its different videos.
4. How many hours of everyday study can help?
   Studying for two hours every day can help in doing good preparations.