This quiz works best with JavaScript enabled. Home > Cbse > Class 9 > Science > Atoms And Molecules > Class 9 Science Chapter 3 Atoms And Molecules – Quiz 6 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 9 Science Chapter 3 Atoms And Molecules Quiz 6 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. 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). 2. 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. 3. 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. 4. What charge do cations carry A) Positive. B) Neutral. C) Negative. D) None. Show Answer Correct Answer: A) Positive. 5. 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. 6. The smallest unit of an element that still has the properties of that element. A) Nucleus. B) Adam. C) Atom. D) Element. Show Answer Correct Answer: C) Atom. 7. The number of atoms constituting a molecule is known as its A) Element. B) Atomicity. C) Ions. D) Compound. Show Answer Correct Answer: B) Atomicity. 8. Father of modern chemistry is ..... A) Joseph L Proust. B) Antoine Lavoisier. C) John Dalton. D) Rutherford. Show Answer Correct Answer: B) Antoine Lavoisier. 9. 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. 10. What is the electron? A) A neutral particle that orbits the nucleus. B) A positively charged particle found in the nucleus. C) A negatively charged particle that orbits the nucleus. D) A neutral particle found in the nucleus. Show Answer Correct Answer: C) A negatively charged particle that orbits the nucleus. 11. Which of the following contains maximum number of molecules? A) 1 g N$_{2}$. B) 1 g H$_{2}$. C) 19 CO$_{2}$. D) 1 g CH$_{4}$. Show Answer Correct Answer: B) 1 g H$_{2}$. 12. Particles in an atom that are neutral and have no charge are A) Negrone. B) Electrons. C) Protons. D) Neutrons. Show Answer Correct Answer: D) Neutrons. 13. Who presented the atomic theory A) Albert Einstein. B) John Dalton. C) Marie Curie. D) Robert Hooke. Show Answer Correct Answer: B) John Dalton. 14. Which law states that mass can neither be created nor destroyed in a chemical reaction? A) Law of Conservation of Mass. B) Law of Multiple Proportions. C) Avogadro's Law. D) Law of Constant Proportions. Show Answer Correct Answer: A) Law of Conservation of Mass. 15. Which law states that in a chemical substance, the elements are always present in definite proportions by mass? A) Law of Variable Proportions. B) Law of Definite Proportions. C) Law of Conservation of Mass. D) Law of Multiple Proportions. Show Answer Correct Answer: B) Law of Definite Proportions. 16. 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. 17. The element whose gm atomic mass and gm molecular mass is same A) Hydrogen. B) Sodium. C) Nitrogen. D) Oxygen. Show Answer Correct Answer: B) Sodium. 18. How many atoms are there is Na2CO3 A) 6. B) 5. C) 7. D) 4. Show Answer Correct Answer: A) 6. 19. According to Daltons's Atomic theory, "The relative number and kinds of atoms are constant in a given compound." postulate describes A) Law of Conservation of Mass. B) Law of Constant Proportion. C) All the above. D) None of the above. Show Answer Correct Answer: B) Law of Constant Proportion. 20. Atom is from a Greek word 'atomos' that means A) Energy. B) Matter. C) Building block. D) Incapable of being cut. Show Answer Correct Answer: D) Incapable of being cut. 21. If a reaction starts with a total 75g of reactants it should produce A) A total of 40g of products. B) A total of 75g of products. C) A total of 180 g of products. D) None of the above. Show Answer Correct Answer: B) A total of 75g of products. 22. Atomic Mass of H, C, O *Choose the correct option in order A) (1, 1, 100)amu. B) (1, 12, 16)u. C) X g. D) (16, 12, 0)u. Show Answer Correct Answer: B) (1, 12, 16)u. 23. The Latin name of gold A) Auram. B) Sodium. C) Potassium. D) None. Show Answer Correct Answer: A) Auram. 24. In which forms do atoms exist A) Ions. B) Molecules. C) Free electrons. D) Both A and B. Show Answer Correct Answer: D) Both A and B. 25. Who gave the law of chemical reaction ..... A) Joseph proust. B) Antoine Lavoisier. C) Both a and b. D) None of the above. Show Answer Correct Answer: C) Both a and b. 26. Which one of these is the correct symbol for mercury A) Me. B) Hg. C) HG. D) Me. Show Answer Correct Answer: B) Hg. 27. Atomicity is ..... A) The number of atoms present in an element. B) The number of atoms present in a molecule. C) Atomic mass. D) None of the above. Show Answer Correct Answer: B) The number of atoms present in a molecule. 28. What is the chemical symbol for the element mercury? A) Hg. B) MY. C) Merc. D) MeC. Show Answer Correct Answer: A) Hg. 29. Anything that has mass & takes up space A) Matter. B) Volume. C) Force. D) Gravity. Show Answer Correct Answer: A) Matter. 30. The beginning substances in a chemical reaction are called ..... A) Reactants. B) Products. C) All the above. D) None of the above. Show Answer Correct Answer: A) Reactants. 31. Who laid the foundation of laws of chemical combination? A) Democritus and Leupipus. B) Antoine L. Lavoisier. C) John Dalton. D) None of the above. Show Answer Correct Answer: B) Antoine L. Lavoisier. 32. Approximately how many atoms can you fit on the head of a pin? A) 1, 000. B) 1, 000, 000. C) 1, 000, 000, 000. D) 100. Show Answer Correct Answer: C) 1, 000, 000, 000. 33. Atoms of the same element which have a different number of neutrons are called ..... A) Isotopes. B) Molecules. C) Ions. D) Quarks. Show Answer Correct Answer: A) Isotopes. 34. Name two scientist who established the laws of chemical combination A) Antoine L LAVOISER AND JOSEPH L PROUST. B) Anthony Lavoiser and Joseph Proust. C) Anthony L Proust and Joseph L LAVOISER. D) Mr.Hooke and Isaac Newton. Show Answer Correct Answer: A) Antoine L LAVOISER AND JOSEPH L PROUST. 35. The volume of atom is about ..... times the volume of nucleus A) 10$^{5}$. B) 10$^{20}$. C) 10$^{15}$. D) 10$^{10}$. Show Answer Correct Answer: C) 10$^{15}$. 36. What charge does an atom have when it GAINS electrons? A) Positive. B) Negative. C) Neutral. D) None of the above. Show Answer Correct Answer: B) Negative. 37. What is the molecular mass of $HNO_3$ A) Struggle. B) Grate. C) Stab. D) 61 u. Show Answer Correct Answer: C) Stab. 38. How many H atoms are in H$_{2}$O? A) 1. B) 2. C) All the above. D) None of the above. Show Answer Correct Answer: B) 2. 39. We will celebrate the ..... Republic day on 26th Jan 2022. A) Actually. B) Cute. C) 69th. D) Gang. Show Answer Correct Answer: D) Gang. 40. The reference standard used for defining atomic mass unit is A) O-16. B) C-12. C) H-1. D) C-13. Show Answer Correct Answer: B) C-12. 41. Which has more number of atoms, 100g of Sodium or 100g of Iron A) Sodium. B) Fes. C) Fe. D) Iron. Show Answer Correct Answer: A) Sodium. 42. Which unit is used to express atomic mass? A) Mole. B) Atomic Mass Unit (amu). C) Gram. D) Kilogram. Show Answer Correct Answer: B) Atomic Mass Unit (amu). 43. Which of the following is a neutral oxide? A) N $ _ {2} $ O $ _ {5} $. B) CO$_{2}$. C) CO. D) At $ _ {2} $ o $ _ {3} $. Show Answer Correct Answer: C) CO. 44. John Dalton stated: A) Elements are made of atoms. B) Atoms of a given element are identical. C) Atoms cannot be subdivided, created, nor destroyed. D) All of the above. Show Answer Correct Answer: D) All of the above. 45. The ratio of of H and O in H2O by mass is A) 1:8. B) 1:9. C) 1:7. D) 1:6. Show Answer Correct Answer: A) 1:8. 46. Which of the following is tetra atomic A) Sulphur. B) Phosphorus. C) Oxygen. D) Potassium. Show Answer Correct Answer: B) Phosphorus. 47. The bonding capacity of an element is called ..... A) Valency. B) Molecular mass. C) Atomic Mass Unit. D) Atomic number. Show Answer Correct Answer: A) Valency. 48. Which cell may be up to 1 m long? A) Cardiac muscle cell. B) Nerve cell. C) Collagen fibre cell. D) Non-striated ( unstriated). Show Answer Correct Answer: B) Nerve cell. 49. Identify Nitrogen gas A) 2N. B) N$_{2}$. C) N. D) NO. Show Answer Correct Answer: B) N$_{2}$. 50. How many atoms are contained in 25 g of NaBr? (Atomic mass of Na = 23, Br = 35) A) 0.24 molecules. B) 102.96 molecules. C) 2.34 x 10$^{20}$molecules. D) 1.45x10$^{23}$ molecules. Show Answer Correct Answer: D) 1.45x10$^{23}$ molecules. 51. 1 u or 1 amu means A) Mass of O-16 atom. B) Mass of C-12 atom. C) 1/12th mass of C-12 atoms. D) Mass of Hydrogen molecule. Show Answer Correct Answer: B) Mass of C-12 atom. 52. Calcium and oxygen are present in which of the following compounds? A) Potassium Sulphate. B) Hydrogen Bromide. C) Quick Lime. D) Baking Soda. Show Answer Correct Answer: C) Quick Lime. 53. Which law states that in a chemical substance the elements are always present in definite proportion by mass and given by ..... A) Law of conservation of mass, Proust. B) Law of constant proportion, Lavosier. C) Law of constant proportion, Proust. D) None of the above. Show Answer Correct Answer: C) Law of constant proportion, Proust. 54. What are the basic building blocks for all matter? A) Chemicals. B) Atoms. C) Elements. D) Compounds. Show Answer Correct Answer: B) Atoms. 55. Law of constant proportion is also referred to as law of definite proportion A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 56. The law of conservation of mass states that ..... A) The total mass of reactants is more than the total mass of products. B) The total mass of reactants is less than the total mass of products. C) The mass of a chemical reaction is not constant. D) The mass of a chemical reaction remains constant. Show Answer Correct Answer: D) The mass of a chemical reaction remains constant. 57. The symbol for the metal used in thermometer. A) Sg. B) Mg. C) Ag. D) Hg. Show Answer Correct Answer: D) Hg. 58. ..... is the smallest particle that takes part in a chemical reaction. A) Compound. B) Atoms. C) Ion. D) Molecule. Show Answer Correct Answer: B) Atoms. 59. Who was the English Chemist that developed the Atomic Theory? A) Democritus. B) John Dalton. C) Socrates. D) James Bond. Show Answer Correct Answer: B) John Dalton. 60. What is the chemical name of CsI? A) Cesium Iodide. B) Cesium Monoiodide. C) Carbon Silicate. D) Carbon Sulfide Iodide. Show Answer Correct Answer: A) Cesium Iodide. ← PreviousNext →Related QuizzesScience QuizzesClass 9 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 7 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books