This quiz works best with JavaScript enabled. Home > Class 9 > Class 9 Science Chapter 3 Atoms And Molecules – Quiz 12 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 9 Science Chapter 3 Atoms And Molecules Quiz 12 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. The combining power (or capacity) of an element is known as its A) Valency. B) Valence electrons. C) Charge. D) Oxidation number. Show Answer Correct Answer: A) Valency. 2. Two or more atoms chemically bonded together are called a A) Atom. B) Element. C) Molecule. D) Mixture. Show Answer Correct Answer: C) Molecule. 3. Who was the first scientist to use symbols for elements in a very specific sense. A) Avagadro. B) Lavoisier. C) Dalton. D) Rutherford. Show Answer Correct Answer: C) Dalton. 4. The reactants of the equation CO$_{2}$ + 2H$_{2}$ $\rightarrow$ CH$_{3}$OH is: A) CO$_{2}$ and H$_{2}$. B) Only H$_{2}$. C) CO$_{2, }$H$_{2 }$and CH$_{3}$OH. D) CO$_{2 }$and CH$_{3}$OH. Show Answer Correct Answer: A) CO$_{2}$ and H$_{2}$. 5. One atomic mass unit is a mass unit equal to exactly Carbon A) 1/16th. B) 1/12th. C) 1/10th. D) 1/14th. Show Answer Correct Answer: B) 1/12th. 6. Hydrogen and oxygen combine in the ratio of 1:8 by mass to form water. What mass of hydrogen would be required to react completely with 56 g of oxygen gas? A) 448 g. B) 8 g. C) 7 g. D) 1 g. Show Answer Correct Answer: C) 7 g. 7. What is the symbol for gold? A) Go. B) Au. C) Ag. D) Gl. Show Answer Correct Answer: B) Au. 8. Atomicity of chlorine and ozone A) Monoatomic, triatomic. B) Diatomic, triatomic. C) Monoatomic, tetratomic. D) Both are monoatomic. Show Answer Correct Answer: B) Diatomic, triatomic. 9. ASSERTION:Law of conservation of mass holds good for all the reactions REASON:It states that energy can neither be created nor be distroyed in an chemical reaction. A) A and R both are true and R is correct explanation of A. B) A and R both are true but R is not correct explanation of A. C) A is true but R i false. D) A is false but R is true. Show Answer Correct Answer: A) A and R both are true and R is correct explanation of A. 10. What makes one atom different from another? A) The atomic number. B) The number of protons in the nucleus. C) The number of electrons. D) The number of atoms. Show Answer Correct Answer: B) The number of protons in the nucleus. 11. Which one will have more number of molecules in the given samples? A) 3 moles of CO$_{2}$. B) 2 moles of NH$_{3}$. C) 1 mole of H$_{2}$SO$_{4}$. D) None of the above. Show Answer Correct Answer: A) 3 moles of CO$_{2}$. 12. What is a molecule? A) Two elements bonded together (sharing electrons). B) A mixture of different substances. C) Smallest individual particles. D) Salt mixed in water. Show Answer Correct Answer: A) Two elements bonded together (sharing electrons). 13. The valency of the halogen present in second period is ..... A) 1. B) 3. C) 5. D) 7. Show Answer Correct Answer: A) 1. 14. G of CO$_{2}$ is equal to ..... mol A) 0.1. B) 0.2. C) 2.0. D) 0.3. Show Answer Correct Answer: A) 0.1. 15. Symbol for Gold is ..... A) F. B) Au. C) Go. D) Pb. Show Answer Correct Answer: B) Au. 16. Q7) An atom has a mass number of 23 and atomic number of 11. The number of neutrons are A) 23. B) 11. C) 12. D) None of these. Show Answer Correct Answer: C) 12. 17. Atomic mass of hydrogen is 1 u whereas atomic mass of helium is 4 u. From this, we can generally conclude that 1 mole of hydrogen will have same mass as ..... moles of helium. A) 1. B) 4. C) 0.5. D) 0.25. Show Answer Correct Answer: D) 0.25. 18. The nitrogen in air has two nitrogen atoms bonded together. This nitrogen is A) A compound. B) An element. C) A molecule. D) An atom. Show Answer Correct Answer: C) A molecule. 19. Which of the following elements is diatomic in nature? A) Helium. B) Neon. C) Oxygen. D) Carbon. Show Answer Correct Answer: C) Oxygen. 20. How many Sulfur atoms are in this compound? Al$_{2}$(SO$_{4}$)$_{3}$ A) 4. B) 2. C) 3. D) 1. Show Answer Correct Answer: C) 3. 21. Name the elements represented by following symbols:Pb Sn A) Lead. Aluminium. B) Lead, Tin. C) Tin. Copper. D) Hydrogen., Boron. Show Answer Correct Answer: B) Lead, Tin. 22. When 3.0 g of carbon is burnt in 8.00 g oxygen, 11.00 g of carbon dioxide is produced. What mass of carbon dioxide will be formed when 3.00 g of carbon is burnt in 50.00 g of oxygen? A) 53 g. B) 47 g. C) 11 g. D) 14 g. Show Answer Correct Answer: C) 11 g. 23. What does conservation of matter mean? A) Matter cycles through an ecosystem and 10% is lost as you move through each trophic level. B) Matter cannot be created, but can be destroyed. C) Matter cannot be created nor destroyed, and cycles through ecosystems. D) Matter and energy both move through ecosystems with 100% efficiency. Show Answer Correct Answer: C) Matter cannot be created nor destroyed, and cycles through ecosystems. 24. Sodium chloride (NaCl) is not a molecule. (True/False) A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 25. When you cool matter, what happens to the atoms and molecules? A) They move faster. B) They move slower. C) They stop moving. D) They stay the same. Show Answer Correct Answer: B) They move slower. ← 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