Get comprehensive solutions to all NCERT Class 9 Science questions with detailed explanations. Our expert-prepared answers help you understand concepts better and score excellent marks in your exams.
Q1. What are the characteristics of particles of matter?
Answer: The characteristics of particles of matter are:
Q2. Define matter and give examples.
Answer: Matter is anything that occupies space and has mass. Examples include air, water, wood, stone, iron, ice, etc. All physical objects around us are made of matter.
Q3. What is the difference between evaporation and boiling?
Answer:
| Evaporation | Boiling |
|---|---|
| Occurs at any temperature | Occurs at a specific temperature |
| Surface phenomenon | Bulk phenomenon |
| Slow process | Fast process |
Q1. What is an atom? Who coined this term?
Answer: An atom is the smallest particle of an element that cannot be divided further by chemical means. The term 'atom' was coined by the Greek philosopher Democritus.
Q2. State the law of conservation of mass.
Answer: The law of conservation of mass states that mass can neither be created nor destroyed in a chemical reaction. The total mass of reactants is equal to the total mass of products.
Q3. Calculate the molecular mass of water (H₂O).
Answer:
Molecular mass of H₂O = 2 × Atomic mass of H + 1 × Atomic mass of O
= 2 × 1 + 1 × 16 = 2 + 16 = 18 u
Q1. What is the difference between distance and displacement?
Answer:
Q2. Define uniform and non-uniform motion.
Answer:
Q3. What are the equations of motion?
Answer: The three equations of motion are:
Where: v = final velocity, u = initial velocity, a = acceleration, t = time, s = displacement
Q1. Who discovered the cell and when?
Answer: The cell was discovered by Robert Hooke in 1665 when he observed cork cells under a microscope.
Q2. What is the difference between prokaryotic and eukaryotic cells?
Answer:
| Prokaryotic Cells | Eukaryotic Cells |
|---|---|
| No well-defined nucleus | Well-defined nucleus |
| No membrane-bound organelles | Membrane-bound organelles present |
| Example: Bacteria | Example: Plant and animal cells |
Q3. What is the function of mitochondria?
Answer: Mitochondria are called the powerhouse of the cell because they produce energy (ATP) through cellular respiration. They are the sites of aerobic respiration.
Q: How many chapters are there in Class 9 Science?
A: There are 15 chapters in NCERT Class 9 Science covering Physics, Chemistry, and Biology.
Q: Are these solutions helpful for board exams?
A: Yes, these solutions are specifically designed to help students prepare for CBSE board exams and score excellent marks.
Q: Do you provide solutions for all exercise questions?
A: Yes, we provide complete solutions for all in-text questions, exercise questions, and additional practice questions.
