This quiz works best with JavaScript enabled. Home > Class 9 > Class 9 Science Chapter 4 Structure Of The Atom – Quiz 2 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 9 Science Chapter 4 Structure Of The Atom Quiz 2 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. Radiation emitted by a certain radioisotope is used to kill bacteria and other microorganisms in foods such as potatoes. What is the isotope? A) Carbon-14. B) Cobalt-60. C) Iodine-131. D) Phosphorus-32. Show Answer Correct Answer: B) Cobalt-60. 2. If the number of electrons in an atom changes you make a(n) ..... A) Ion. B) Isotope. C) New element. D) Isomer. Show Answer Correct Answer: A) Ion. 3. What is the subtopic of atomic structure? A) Arrangement of subatomic particles. B) Behavior of sound waves. C) Classification of chemical elements. D) Study of plant cells. Show Answer Correct Answer: A) Arrangement of subatomic particles. 4. The first model of an atom was given by A) N. Bohr. B) E. Goldstein. C) Rutherford. D) J.J. Thomson. Show Answer Correct Answer: D) J.J. Thomson. 5. WhIch sub atomic particle vary between isotopes of an element? A) Protons, electrons, and atomic mass. B) Protons, electrons, and atomic number. C) Neutrons and electrons. D) Neutrons only. Show Answer Correct Answer: D) Neutrons only. 6. Which atomic model proposed the presence of electrons inside a positive sphere? A) Thomson's Atomic Model. B) Rutherford's Atomic Model. C) Bohr's Atomic Model. D) Quantum Mechanical Model. Show Answer Correct Answer: A) Thomson's Atomic Model. 7. What are valence electrons? A) Electrons in the first orbital always. B) Nucleus. C) The outermost shell. D) The number of electrons present in the outermost orbital. Show Answer Correct Answer: D) The number of electrons present in the outermost orbital. 8. Isotopes have different number of? A) Protons. B) Electrons. C) Neutrons. D) Protons and Neutrons. Show Answer Correct Answer: C) Neutrons. 9. Electrons where introduced by A) J J Thomson. B) Ernest Rutherford. C) Neil Bohr. D) None of the above. Show Answer Correct Answer: A) J J Thomson. 10. Who stated that atoms cannot be divided? A) Rutherford. B) Dalton. C) Bohr. D) Thomson. Show Answer Correct Answer: B) Dalton. 11. The sum of the protons and neutrons in a nucleus is ..... A) The atomic number. B) The mass number. C) Avogadro's number. D) The element number the element number. Show Answer Correct Answer: B) The mass number. 12. The rays and particles-alpha and beta particles and gamma rays-that are emitted by radioactive materials A) Radiation. B) Radioactive decay. C) Radioactivity. D) Cathode ray. Show Answer Correct Answer: A) Radiation. 13. According to Aufbau principle, which orbital fills after the 4s orbital? A) 4p. B) 5s. C) Zd. D) 4f. Show Answer Correct Answer: C) Zd. 14. Of the atom's mass is found where? A) Nucleus. B) Protons. C) Electron cloud. D) Neutrons. Show Answer Correct Answer: A) Nucleus. 15. A particle with two protons and two neutrons, with a 2+ charge; is equivalent to a helium-4 nucleus, can be represented by $\alpha$; and is emitted during radioactive decay A) Alpha particle. B) Alpha radiation. C) Beta particle. D) Gamma ray. Show Answer Correct Answer: A) Alpha particle. 16. An electron has this charge A) Positive. B) Negative. C) Neutral. D) None of the above. Show Answer Correct Answer: B) Negative. 17. What atom matches this electron configuration?1s$^{2}$2s$^{2}$2p$^{6}$3s$_{}$$^{2}$ A) Neon. B) Magnesium. C) Aluminum. D) Potassium. Show Answer Correct Answer: B) Magnesium. 18. What is an atom made up of? A) Protons and neutrons. B) Protons and electrons. C) Neutrons and electrons. D) Protons, neutrons, and electrons. Show Answer Correct Answer: D) Protons, neutrons, and electrons. 19. Helium atom has an atomic mass of 4u and two protons in its nucleus. How many neutrons does it have? A) 2. B) 4. C) 3. D) 0. Show Answer Correct Answer: A) 2. 20. What is the symbol of manganese? A) Mg. B) M. C) Ma. D) Mn. Show Answer Correct Answer: D) Mn. 21. What is the mass number of an atom which contains 28 protons, 28 electrons, and 34 neutrons? A) 28. B) 56. C) 62. D) 90. Show Answer Correct Answer: C) 62. 22. Isotopes of the same element have ..... A) The same number of protons but different numbers of neutrons. B) The same number of protons but different numbers of electrons. C) The same number of neutrons but different numbers of protons. D) The same number of neutrons but different numbers of electrons. Show Answer Correct Answer: A) The same number of protons but different numbers of neutrons. 23. What quantities vary between isotopes of an element? A) Protons, electrons, and atomic mass. B) Protons, electrons, and atomic number. C) Neutrons and electrons. D) Neutrons and atomic mass. Show Answer Correct Answer: D) Neutrons and atomic mass. 24. Three isotopes of oxygen occur in nature:oxygen-16, oxygen-17, and oxygen-18. If the atomic mass of oxygen is 15.9994, which of the three isotopes, if any, is the most abundant? A) Oxygen-16. B) Oxygen-17. C) Oxygen-18. D) All are equally abundant. Show Answer Correct Answer: A) Oxygen-16. 25. Where are Protons located in an atom? A) Electron cloud. B) Nucleus. C) Outside. D) Around. Show Answer Correct Answer: B) Nucleus. ← PreviousNext →Related QuizzesClass 9 Science Chapter 4 Structure Of The Atom Quiz 1Class 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 7Class 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