Subject: General Science
Book: NCERT Science Class 9
Atoms are the basic units of matter.
- **Laws of Chemical Combination**:
- Law of Conservation of Mass.
- Law of Constant Proportion.
- **Concept of Molecules**:
- Molecules of elements: O₂, N₂.
- Molecules of compounds: H₂O, CO₂.
- **Chemical Formulae**:
- Represent the composition of a compound (H₂O for water).
- **Mole Concept**:
- 1 mole = 6.022 × 10²³ particles.
**Possible Exam Questions:**
1. State the laws of chemical combination.
2. Differentiate between atoms and molecules.
3. What is the significance of a chemical formula?
4. How is the mole concept used in chemistry?
5. Explain Avogadro’s number with an example.
Which part of the cell is responsible for energy production?
View QuestionWhich element has the highest electrical conductivity?
View QuestionWhich organelle is responsible for photosynthesis in plants?
View QuestionWhich gas is commonly used in balloons to make them float?
View QuestionWhat is the primary function of white blood cells?
View QuestionWhich of the following is a fundamental force in nature?
View QuestionWhich disease is caused by a virus?
View QuestionWhich part of the brain is responsible for balance and coordination?
View QuestionWhat is the boiling point of water at standard atmospheric pressure?
View QuestionWhich part of the human eye is responsible for focusing light on the retina?
View Question