This quiz works best with JavaScript enabled. Home > Class 9 > Class 9 Science Chapter 4 Structure Of The Atom – Quiz 12 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 9 Science Chapter 4 Structure Of The Atom Quiz 12 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. We know that objects with like electric charge repel one another. Which statement best explains why protons can remain close to one another in a nucleus? A) There is no electric charge in the nucleus of an atom. B) A short-range force, called the strong nuclear force, binds protons together. C) Protons are balanced electrically by electrons. D) Neutrons cancel out the electric force. Show Answer Correct Answer: B) A short-range force, called the strong nuclear force, binds protons together. 2. What law states that, regardless of the amount, a compound is always composed of the same elements in the same proportion by mass? A) Law of definite proportions. B) Law of conservation of mass. C) Law of multiple proportions. D) Law of mass action. Show Answer Correct Answer: A) Law of definite proportions. 3. Canal rays discovered by E. Goldstein contained particles that were: A) Neutral. B) Positively charged. C) Negatively charged. D) None of these. Show Answer Correct Answer: B) Positively charged. 4. Which model of the atom first introduced the concept of quantized electron orbits? A) Bohr model. B) Rutherford model. C) Thomson model. D) Quantum mechanical model. Show Answer Correct Answer: A) Bohr model. 5. Who discovered the presence of neutrons in the atom? A) John Dalton. B) J.J. Thomson. C) E. Goldstein. D) J. Chadwick. Show Answer Correct Answer: D) J. Chadwick. 6. Which isotope of carbon is used in carbon dating? A) Carbon-14. B) Carbon-13. C) Carbon-12. D) None of the above. Show Answer Correct Answer: A) Carbon-14. 7. ..... is the universal solvent because it dissolves most substances. A) Oxygen. B) Water. C) Salt. D) Gatorade. Show Answer Correct Answer: B) Water. 8. What did Rutherford conclude from his $\alpha$-ray scattering experiment? A) Atom consists of predominantly empty space. B) Atom contains a centrally placed positively charged nucleus. C) Most of the space in an atom is empty. D) All of the above. Show Answer Correct Answer: D) All of the above. 9. If reaction starts with 20g of reactants it should produce A) A total of 40g of products. B) A total of 10g of products. C) A total of 80 g of products. D) A total of 20g of products. Show Answer Correct Answer: D) A total of 20g of products. 10. A neutron has this charge A) Negative. B) Positive. C) Neutral. D) None of the above. Show Answer Correct Answer: C) Neutral. 11. Except for in the simplest type of hydrogen atom, all nuclei consist of A) Protons and electrons. B) Neutrons and positrons. C) Protons and neutrons. D) Electrons and positrons. Show Answer Correct Answer: C) Protons and neutrons. 12. What is correct about electrons? A) Are negatively charged subparticles found in the electron cloud. B) Are positively charged subparticles found in energy levels. C) Are subparticles with no charge found in the electron cloud. D) Are negatively charged particles found in the nucleus. Show Answer Correct Answer: A) Are negatively charged subparticles found in the electron cloud. 13. The only element with no neutrons in its nucleus. A) Lithium. B) Hydrogen. C) Helium. D) Oxygen. Show Answer Correct Answer: C) Helium. 14. Atoms are electrically neutral when A) They have a minimal charge. B) They have a balanced number of protons and neutrons. C) They have a balanced number of protons and electrons. D) They have no valance electrons. Show Answer Correct Answer: C) They have a balanced number of protons and electrons. 15. Who discovered the electron? A) Rutherford. B) Chadwick. C) Thomson. D) Goldstein. Show Answer Correct Answer: C) Thomson. 16. Who discovered the presence of electrons in the atom? A) John Dalton. B) J.J. Thomson. C) E. Goldstein. D) J. Chadwick. Show Answer Correct Answer: B) J.J. Thomson. 17. How many p orbitals are there in a sublevel? A) 2. B) 1. C) 4. D) 3. Show Answer Correct Answer: D) 3. 18. Drawback of Rutherford model is? A) Shape of orbitals is circular. B) Nucleons are at the center. C) Electrons deflected alpha rays. D) None of the above. Show Answer Correct Answer: A) Shape of orbitals is circular. 19. The total volume of the nucleus of an atom is A) Very large compared with the rest of the atom. B) Very small compared with the rest of the atom. C) About the same size as an electron. D) Smaller than a neutron. Show Answer Correct Answer: B) Very small compared with the rest of the atom. 20. Which of these has a negative charge? A) Proton. B) Neutron. C) Electron. D) Oatmeal. Show Answer Correct Answer: C) Electron. 21. The central region of an atom where its neutrons and protons are is its ..... A) Core. B) Nucleus. C) Electron cloud. D) Centre. Show Answer Correct Answer: B) Nucleus. 22. The nucleus is ..... charged. A) Positively. B) Negatively. C) Neutral. D) None of the above. Show Answer Correct Answer: A) Positively. 23. Which of these things would be considered subatomic? A) Copper. B) Electron. C) Water molecule. D) Oxygen. Show Answer Correct Answer: B) Electron. 24. Which of the following represent electronic distribution in magnesium atom A) 3, 8, 1. B) 2, 8, 2. C) 1, 8, 3. D) 8, 2, 2. Show Answer Correct Answer: B) 2, 8, 2. 25. ..... is the lowest energy level an electron will occupy in an atom at an ordinary condition A) Ground state. B) Excited state. C) Highest state. D) None of the above. Show Answer Correct Answer: A) Ground state. ← 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 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 10 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books