This quiz works best with JavaScript enabled. Home > Class 9 > Class 9 Science Chapter 4 Structure Of The Atom – Quiz 7 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 9 Science Chapter 4 Structure Of The Atom Quiz 7 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. High-energy radiation that has no electrical charge and no mass, is not deflected by electric or magnetic fields, usually accompanies alpha and beta radiation, and accounts for most of the energy lost during radioactive decay A) Gamma ray. B) Cathode ray. C) Radiation. D) Radioactivity. Show Answer Correct Answer: A) Gamma ray. 2. One-twelfth the mass of a carbon-12 atom A) Atomic mass unit. B) Atomic mass. C) Mass number. D) Atomic number. Show Answer Correct Answer: A) Atomic mass unit. 3. Rutherford realized that the atomic nucleus was positively charged because A) It attracted alpha particles. B) It deflected alpha particles. C) It had no effect on alpha particles. D) It produced alpha particles. Show Answer Correct Answer: B) It deflected alpha particles. 4. An element has 5 valence electron, what is its valency? A) 4. B) 3. C) 2. D) 1. Show Answer Correct Answer: B) 3. 5. What are isotopes?ELEMENTS having the A) Same atomic no, but different mass no. B) Same mass no, different valency. C) Same mass no and atomic no. D) None of the above. Show Answer Correct Answer: A) Same atomic no, but different mass no. 6. The number of protons in an atom A) Atomic number. B) Mass number. C) Atomic mass. D) Atomic mass unit. Show Answer Correct Answer: A) Atomic number. 7. The extremely small, positively charged, dense center of an atom that contains positively charge protons and neutral neutrons A) Nucleus. B) Protons. C) Electron. D) Neutron. Show Answer Correct Answer: A) Nucleus. 8. Which element would be inert in nature? A) Element with 2 electrons. B) Element with 9 electrons. C) Element with 12 electrons. D) Element with 20 electrons. Show Answer Correct Answer: A) Element with 2 electrons. 9. Which statement correctly describes the location and charge of the neutrons in an atom? A) The neutrons are inside the nucleus and have a positive charge. B) The neutrons are outside the nucleus and have a neutral charge. C) The neutrons are outside the nucleus and have a negative charge. D) The neutrons are inside the nucleus and have a neutral charge. Show Answer Correct Answer: D) The neutrons are inside the nucleus and have a neutral charge. 10. An element can be defined by the number of ..... in the nucleus of its atoms. A) Protons. B) Neutrons. C) Electrons. D) Atoms. Show Answer Correct Answer: A) Protons. 11. Quarks make up which two subatomic particles? A) Protons and neutrons. B) Protons and electrons. C) Neutrons and electrons. D) Protons and ions. Show Answer Correct Answer: A) Protons and neutrons. 12. Which of the following sets of particles would have a relative mass of approximately 12 amu and a neutral charge? A) 6 protons and 6 electrons. B) 12 neutrons and 12 electrons. C) 3 protons, 3 neutrons and 6 electrons. D) 6 protons, 6 neutrons and6 electrons. Show Answer Correct Answer: D) 6 protons, 6 neutrons and6 electrons. 13. The Expriment of Gold foil was about ..... thick A) 10 atoms. B) 1000 atoms. C) 100 atoms. D) None of the above. Show Answer Correct Answer: B) 1000 atoms. 14. What is valence electrons? A) The electron present in the innermost shell. B) The electron present in the 3rd or the 4rd shell. C) The electron present in the outermost shell. D) None of the above. Show Answer Correct Answer: C) The electron present in the outermost shell. 15. Who discovered the nucleus of an atom? A) JJ Thomson. B) John Dalton. C) Ernest Rutherford. D) Democritus. Show Answer Correct Answer: C) Ernest Rutherford. 16. An atom of $U_{92}^{238}$ A) 92, 146. B) 146, 92. C) 330, 92. D) 238, 146. Show Answer Correct Answer: A) 92, 146. 17. A certain element is known to exist as two different isotopes. State one thing that is the same for atoms of both isotopes. A) The number of protons. B) The number of nucleons. C) The number of neutrons. D) The number of quarks. Show Answer Correct Answer: A) The number of protons. 18. Which of the following is NOT a part of Dalton's atomic theory? A) Atoms cannot be divided, created or destroyed. B) The number of protons in an atom is its atomic number. C) In chemical reactions, atoms are combined, separated or rearranged. D) All matter is composed of extremely small particles called atoms. Show Answer Correct Answer: B) The number of protons in an atom is its atomic number. 19. In an atom, electrons move in definite orbits around the nucleus. A) Dalton. B) Neil Bohr. C) Thompson. D) Rutherford. Show Answer Correct Answer: B) Neil Bohr. 20. The ion of an element has 3 positive charges. Mass number of the atom is 27 and the number of neutrons is 14. What is the number of electrons in the ion? A) 13. B) 10. C) 14. D) 16. Show Answer Correct Answer: B) 10. 21. The number 80 in the name bromine-80 represents ..... A) The atomic number. B) The mass number. C) The sum of protons and electrons. D) None of the above. Show Answer Correct Answer: B) The mass number. 22. The mass of a helium atom is twice that of a hydrogen atom A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: B) False. 23. What is the central part of an atom called, which contains protons and neutrons? A) Electron cloud. B) Nucleus. C) Orbit. D) Shell. Show Answer Correct Answer: B) Nucleus. 24. What is the shape of s orbitals? A) Dumbbell shaped. B) Peanut shaped. C) Spherical shaped. D) Hybrid structure. Show Answer Correct Answer: C) Spherical shaped. 25. What is the approximate radius of an atom? A) 1x10$^{-5}$ m. B) 1x10$^{-10}$ m. C) 1x10$^{-15}$ m. D) 1x10$^{-20}$ m. Show Answer Correct Answer: B) 1x10$^{-10}$ m. ← PreviousNext →Related QuizzesClass 9 Science Chapter 4 Structure Of The Atom Quiz 1Class 9 Science Chapter 4 Structure Of The Atom Quiz 2Class 9 Science Chapter 4 Structure Of The Atom Quiz 3Class 9 Science Chapter 4 Structure Of The Atom Quiz 4Class 9 Science Chapter 4 Structure Of The Atom Quiz 5Class 9 Science Chapter 4 Structure Of The Atom Quiz 6Class 9 Science Chapter 4 Structure Of The Atom Quiz 8Class 9 Science Chapter 4 Structure Of The Atom Quiz 9Class 9 Science Chapter 4 Structure Of The Atom Quiz 10Class 9 Science Chapter 4 Structure Of The Atom Quiz 11 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books