Atoms and Molecules Class 9 MCQs with Answers & Solutions
Atoms and Molecules Class 9 MCQs with Answers & Explanations
Class: 9 |
Subject: Science |
Section: Chemistry |
Topic: Atoms and Molecules
Based on: CBSE Board Examinations (NCERT Syllabus)
Based on: CBSE Board Examinations (NCERT Syllabus)
These Multiple Choice Questions (MCQs) are designed strictly as per the NCERT syllabus, making them ideal for CBSE Class 9 Science examination preparation.
1. The smallest unit of an element is:
Answer: B
Explanation: An atom is the smallest particle that retains the chemical properties of an element.
Explanation: An atom is the smallest particle that retains the chemical properties of an element.
2. Law of conservation of mass was given by:
Answer: B — Mass is neither created nor destroyed.
3. Chemical formula of water is:
Answer: B — Two hydrogen atoms + one oxygen atom.
4. Atomicity means:
Answer: B — Example: O₂ has atomicity 2.
5. Avogadro number is:
Answer: A — Number of particles in 1 mole.
6. Mole concept relates mass to:
Answer: C — Connects mass with particles.
7. 1 mole of CO₂ contains:
Answer: C — One mole = Avogadro number molecules.
8. Valency of oxygen is:
Answer: B — Needs two electrons.
9. Relative atomic mass compares mass with:
Answer: B — Standard reference.
10. Chemical formula of sodium chloride:
Answer: C — Ratio 1:1.
11. Dalton proposed:
Answer: A — Matter made of atoms.
12. Molecule of element example:
Answer: A — Same atoms.
13. Gram atomic mass equals:
Answer: A.
14. CO₂ molecular mass:
Answer: A.
15. Law of constant proportions:
Answer: A.
16. Ozone formula:
Answer: B.
17. Atomic mass unit is:
Answer: C.
18. Valency of hydrogen:
Answer: A.
19. Molecule always exists in:
Answer: A.
20. Chemical formula represents:
Answer: D — Complete information.