This quiz works best with JavaScript enabled. Home > Class 9 > Class 9 Science Chapter 3 Atoms And Molecules – Quiz 13 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 9 Science Chapter 3 Atoms And Molecules Quiz 13 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. ..... are substances that are made up of different kinds of atoms. A) Compounds. B) Elements. C) Atoms. D) Use. Show Answer Correct Answer: A) Compounds. 2. "In a chemical reaction, atoms can neither be created nor destroyed." This statement is supported by: A) Law of conservation of mass. B) Law of definite proportion. C) All the above. D) None of the above. Show Answer Correct Answer: A) Law of conservation of mass. 3. Atoms combine to make A) Protons. B) Neutrons. C) Molecules. D) Electrons. Show Answer Correct Answer: C) Molecules. 4. 98u is the molecular mass of A) CO2. B) Caco3. C) H2SO4. D) NH3. Show Answer Correct Answer: C) H2SO4. 5. Three components of atom A) Neutron, Nucleus, Electron. B) Quark, Proton, nucleus. C) Electron, Proton, Neutron. D) None. Show Answer Correct Answer: C) Electron, Proton, Neutron. 6. Valency of inert gas elements. A) 0. B) 2. C) 1. D) 3. Show Answer Correct Answer: A) 0. 7. What is the atomicity of K2CrO4? A) 8. B) 7. C) 10. D) 12. Show Answer Correct Answer: B) 7. 8. What does an atomic number represent? A) How much an atom weighs. B) The number of protons or electrons. C) The sum of protons and electrons. D) The sum of protons and electrons. Show Answer Correct Answer: B) The number of protons or electrons. 9. The magnitude of charge to mass ratio of cathode rays is ..... A) Constant. B) Variable. C) 1.76 x 10$^{11}$ C/kg. D) Both (A) and (C). Show Answer Correct Answer: D) Both (A) and (C). 10. Which statement about atoms is true? A) Atoms combine to make all the substances on Earth. B) Atoms are made up of smaller particles called molecules. C) Atoms come in different sizes, but most are visible using a simple hand lens. D) Atoms combine to make larger subatomic particles. Show Answer Correct Answer: A) Atoms combine to make all the substances on Earth. 11. What two subatomic particles are found in the nucleus? A) Proton and electron. B) Electron and neutron. C) Neutron and proton. D) Neutron and electron. Show Answer Correct Answer: C) Neutron and proton. 12. What charge do cations carry A) Positive. B) Neutral. C) Negative. D) None. Show Answer Correct Answer: A) Positive. 13. Which of the following statements is not true about an atom? A) Atoms are always neutral in nature. B) Atoms are not able to exist independently. C) Atoms are the basic units from which molecules and ions are formed. D) Atoms aggregate in large numbers to form the matter that we can see, feel or touch. Show Answer Correct Answer: D) Atoms aggregate in large numbers to form the matter that we can see, feel or touch. 14. The smallest unit of an element that still has the properties of that element. A) Atom. B) Adam. C) Nucleus. D) Element. Show Answer Correct Answer: A) Atom. 15. The number of atoms constituting a molecule is known as its A) Element. B) Compound. C) Ions. D) Atomicity. Show Answer Correct Answer: D) Atomicity. 16. Father of modern chemistry is ..... A) Antoine Lavoisier. B) Joseph L Proust. C) John Dalton. D) Rutherford. Show Answer Correct Answer: A) Antoine Lavoisier. 17. Which term defines any substance that cannot be broken down into a simpler substance? A) Atom. B) Molecule. C) Element. D) Compound. Show Answer Correct Answer: C) Element. 18. What is the electron? A) A negatively charged particle that orbits the nucleus. B) A neutral particle found in the nucleus. C) A positively charged particle found in the nucleus. D) A neutral particle that orbits the nucleus. Show Answer Correct Answer: A) A negatively charged particle that orbits the nucleus. 19. Which of the following contains maximum number of molecules? A) 19 CO$_{2}$. B) 1 g N$_{2}$. C) 1 g H$_{2}$. D) 1 g CH$_{4}$. Show Answer Correct Answer: C) 1 g H$_{2}$. 20. Particles in an atom that are neutral and have no charge are A) Negrone. B) Electrons. C) Neutrons. D) Protons. Show Answer Correct Answer: C) Neutrons. 21. Who presented the atomic theory A) Albert Einstein. B) John Dalton. C) Robert Hooke. D) Marie Curie. Show Answer Correct Answer: B) John Dalton. 22. Which law states that mass can neither be created nor destroyed in a chemical reaction? A) Law of Constant Proportions. B) Law of Conservation of Mass. C) Law of Multiple Proportions. D) Avogadro's Law. Show Answer Correct Answer: B) Law of Conservation of Mass. 23. Which law states that in a chemical substance, the elements are always present in definite proportions by mass? A) Law of Conservation of Mass. B) Law of Definite Proportions. C) Law of Multiple Proportions. D) Law of Variable Proportions. Show Answer Correct Answer: B) Law of Definite Proportions. 24. An atom has an atomic number of 15 and a mass number of 31. How many protons are there in the atom? A) 15. B) 31. C) 16. D) 47. Show Answer Correct Answer: A) 15. 25. The element whose gm atomic mass and gm molecular mass is same A) Nitrogen. B) Oxygen. C) Sodium. D) Hydrogen. Show Answer Correct Answer: C) Sodium. ← PreviousNext →Related QuizzesClass 9 Science Chapter 3 Atoms And Molecules Quiz 1Class 9 Science Chapter 3 Atoms And Molecules Quiz 2Class 9 Science Chapter 3 Atoms And Molecules Quiz 3Class 9 Science Chapter 3 Atoms And Molecules Quiz 4Class 9 Science Chapter 3 Atoms And Molecules Quiz 5Class 9 Science Chapter 3 Atoms And Molecules Quiz 6Class 9 Science Chapter 3 Atoms And Molecules Quiz 7Class 9 Science Chapter 3 Atoms And Molecules Quiz 8Class 9 Science Chapter 3 Atoms And Molecules Quiz 9Class 9 Science Chapter 3 Atoms And Molecules Quiz 10 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books