Important Topics for CBSE Class 10 Exam

Mathematics:
1. Real Numbers:
- Euclid's division algorithm
- Fundamental theorem of arithmetic
- Irrational numbers
- Rational numbers and their decimal expansions

2. Polynomials:
- Degree and coefficient of a polynomial
- Division algorithm for polynomials
- Remainder and factor theorems
- Algebraic identities

3. Pair of Linear Equations in Two Variables:
- Graphical method of solution
- Algebraic methods of solution
- Equations reducible to a pair of linear equations

4. Quadratic Equations:
- Standard form of a quadratic equation
- Nature of roots
- Relationship between roots and coefficients
- Quadratic formula

5. Arithmetic Progressions:
- nth term of an AP
- Sum of first n terms of an AP
- Word problems related to AP

Science:
1. Chemical Reactions and Equations:
- Types of chemical reactions
- Balancing chemical equations
- Effects of oxidation and reduction reactions
- Corrosion and its prevention

2. Acids, Bases, and Salts:
- pH scale and its importance
- Indicators and their types
- Neutralization reactions
- Preparation and properties of salts

3. Metals and Non-metals:
- Properties of metals and non-metals
- Reactivity series of metals
- Extraction of metals
- Physical and chemical properties of acids

4. Carbon and Its Compounds:
- Covalent bonding
- Nomenclature of organic compounds
- Properties and uses of carbon compounds
- Chemical properties of carbon compounds

5. Periodic Classification of Elements:
- Periodic table and its significance
- Periodicity in properties of elements
- Trends in atomic size, valency, and metallic character
- Uses of noble gases

Social Science:
1. Nationalism in India:
- Rise of nationalism in India
- Partition of Bengal and Swadeshi movement
- Non-cooperation and civil disobedience movements
- Role of Mahatma Gandhi in the Indian freedom struggle

2. Work, Life, and Leisure:
- Changes in the urban landscape
- Growth of industries and factories
- Impact of industrialization on the lives of workers
- Emergence of new forms of entertainment

3. The Age of Industrialization:
- Industrialization in Europe and India
- Impact of industrialization on agriculture
- Emergence of new social classes
- Growth of cities and urbanization

4. Power Sharing:
- Forms of power sharing
- Horizontal and vertical power sharing
- Challenges to power sharing
- Importance of power sharing in a democracy

5. Democracy and Diversity:
- Understanding diversity in India
- Importance of diversity in a democracy
- Challenges to democracy due to diversity
- Measures to promote democracy and diversity

These are some of the important topics and chapters that you should focus on for the CBSE Class 10 exam. Make sure to understand the concepts thoroughly, practice solving numerical problems, and revise regularly to achieve better results in your exam.