This quiz works best with JavaScript enabled. Home > Class 9 > Class 9 Science Chapter 4 Structure Of The Atom – Quiz 8 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 9 Science Chapter 4 Structure Of The Atom Quiz 8 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. The number of neutrons in the nucleus of an atom can be calculated by ..... A) Adding together the numbers of electrons and protons. B) Subtracting the number of protons from the number of electrons. C) Subtracting the number of protons from the mass number. D) Adding the mass number to the number of protons. Show Answer Correct Answer: C) Subtracting the number of protons from the mass number. 2. Solve this equation for alpha decay.$_{8}$$_{5}$$^{209}$At = ..... + $_{2}$$^{4}$He A) $_{83}$$^{205}$Bi. B) $_{86}$$^{209}$Rn. C) $_{81}$$^{207}$Tl. D) $_{85}$$^{208}$At. Show Answer Correct Answer: A) $_{83}$$^{205}$Bi. 3. An atom of Element "Hydrogenn" has 4 electrons, and has 9 nucleons. Mass number is: A) 14u. B) 13u. C) 9U. D) Heard. Show Answer Correct Answer: C) 9U. 4. "ELECTRNOS MOVE AROUND THE NUCLEUS IN DISCRETE ORBITS CALLED IN ENERGY CELLS"This statement is from ..... Model A) Bose. B) Rutherfors. C) J.J Thomson. D) Craydon. Show Answer Correct Answer: A) Bose. 5. Electron is represented by A) P. B) G. C) E. D) C. Show Answer Correct Answer: C) E. 6. A proton has this charge A) Negative. B) Positive. C) Neutral. D) None of the above. Show Answer Correct Answer: B) Positive. 7. Mass of electron is taken as A) 1. B) 2. C) Same as that of proton. D) Negligible. Show Answer Correct Answer: D) Negligible. 8. If K and L shells of an atom are full, then what would be the total no.of electrons in the atom A) 12. B) 10. C) 18. D) 16. Show Answer Correct Answer: B) 10. 9. Cathode rays are composed of particles that are now known as A) Positrons. B) Neutrons. C) Protons. D) Electrons. Show Answer Correct Answer: D) Electrons. 10. The relative atomic mass of an element has no unit. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 11. A high-speed electron with a 1-charge that is emitted during radioactive decay A) Beta particle. B) Beta radiation. C) Alpha particle. D) Gamma ray. Show Answer Correct Answer: A) Beta particle. 12. When an electron absorbs enough energy, it jumps up to a higher level. This is called A) Absorption state. B) Excitation state. C) Emission state. D) Relaxation state. Show Answer Correct Answer: B) Excitation state. 13. Most of an atom is A) Dense. B) Fluid. C) Empty. D) The nucleus. Show Answer Correct Answer: C) Empty. 14. Which element would be most stable 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. 15. Carbon is atomic number 6. What is the mass number of carbon-13? A) 6. B) 7. C) 13. D) None of the above. Show Answer Correct Answer: C) 13. 16. An atom of one of the isotopes of sodium contains:11 protons, 11 electrons and 13 neutrons.State the nucleon number of this isotope. A) 11. B) 13. C) 24. D) 35. Show Answer Correct Answer: C) 24. 17. Which scientist discovered the electrons? A) Dalton. B) Thomson. C) Attractive. D) Bohr. Show Answer Correct Answer: B) Thomson. 18. The sum of the protons and neutrons in an atom equals the ..... A) Atomic number. B) Number of electrons. C) Atomic mass. D) Mass number. Show Answer Correct Answer: D) Mass number. 19. Isotopes are A) The smallest part of an element. B) The number of protons in the nucleus. C) Atoms of the same element that have different numbers of neutrons in the nucleus. D) Atoms that have lost or gained electrons. Show Answer Correct Answer: C) Atoms of the same element that have different numbers of neutrons in the nucleus. 20. What is the role of an electron in an atom? A) Electrons live inside the nucleus and carry a neutral charge. B) Electrons circle the nucleus and have a positive charge. C) Electrons circle the nucleus and have a negative charge. D) Electrons live inside the nucleus and have a negative charge. Show Answer Correct Answer: C) Electrons circle the nucleus and have a negative charge. 21. What is an AMU? A) Atomic multiple unit. B) Atomic mass unit. C) American mass unit. D) None. Show Answer Correct Answer: B) Atomic mass unit. 22. Thomson proposed the modal of an atom to be similar to A) Ice cream. B) Christmas Cake. C) Christmas Pudding. D) Milk shake. Show Answer Correct Answer: C) Christmas Pudding. 23. The no.of proton in an oxygen atom is A) 10. B) 2. C) 8. D) 6. Show Answer Correct Answer: C) 8. 24. How is Proton different from electron? A) An electron is much heavier than a proton. B) An electron carries more charge than a proton. C) A proton can be easily removed from the atom, but not an electron. D) A proton is positively charged, whereas an electron is negatively charged. Show Answer Correct Answer: D) A proton is positively charged, whereas an electron is negatively charged. 25. The mass number gives the number of ..... in the atom. A) Protons and neutrons. B) Protons and electrons. C) Electrons and neutrons. D) Neutrons. Show Answer Correct Answer: A) Protons and neutrons. ← 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 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