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Class 9 Science Chapter 4 Structure Of Atom Quiz 5
Are you ready to put your understanding of atomic structure to the test with our Class 9 Science Chapter 4 quiz? This Structure Of The Atom Quiz 5 is the final part of our series on atomic structure and has been designed to challenge and enhance your knowledge of key concepts from NCERT Class 9 Chapter 4. It’s the perfect way to prepare for your exams in a fun and engaging manner.
Why take this quiz?
The Class 9 chemistry chapter 4 quiz 5 helps students solidify their grasp of fundamental ideas like electrons, protons, neutrons, and their arrangement in an atom. These topics are vital for understanding more advanced science concepts, so testing yourself with multiple-choice quiz questions on structure of the atom is a great way to ensure you’re fully prepared for your upcoming tests.
How does it help?
By solving this 5th quiz on structure of atom class 9, you’ll be able to pinpoint areas that need extra attention while reinforcing the topics you already understand. Quizzes offer instant feedback, which is crucial for boosting your confidence. This quiz for class 9 science chapter 4 will guide you through key points in atomic theory, ensuring you’re ready to face any question that comes your way.
Structure of the Atom Quiz 5 Rules – Class 9 Chemistry
- Time Limit: You have 15 minutes to complete this quiz. Ensure that you manage your time wisely, answering each question promptly but accurately.
- Multiple Choices: Every question will provide you with several answer options. Read through them carefully and select the option that seems most accurate based on your understanding of the concepts from Chapter 4.
- Single Correct Answer: Each question has only one correct answer. Make sure you choose the answer that aligns best with your knowledge of the chapter.
- No Negative Marking: There is no penalty for incorrect answers. If you are unsure of an answer, it’s better to make an educated guess since there are no marks deducted for wrong attempts.
Structure of the Atom Quiz 5 Structure – Class 9 Chemistry
- Total Questions: This quiz contains 10 questions.
- Topics Covered: The quiz focuses on the essential concepts from Chapter 4 – Structure of the Atom. Expect questions on:
- The discovery of subatomic particles (protons, neutrons, and electrons)
- Models of the atom, including J.J. Thomson’s and Rutherford’s models
- Atomic number, mass number, and isotopes
- Distribution of electrons in different shells
This quiz is designed to test your understanding of these foundational concepts, so ensure you’re familiar with all the key ideas discussed in the chapter before attempting it.
Good luck, and remember to stay calm and think critically through each question.
Class 9 Chemistry Chapter 4 Structure Of The Atom Quiz 5 Questions
Question 1: Assertion (A): 1 gm each of hydrogen and deuterium contains the same number of atoms. Reason (R): Hydrogen and deuterium are isobars.
a) Both A and R are true, and R is the correct explanation of A.
b) Both A and R are true, but R is not the correct explanation of A.
c) A is true, but R is false.
d) A and R are false.
Answer:
The correct answer is d) A and R are false.
Actually, 1 gram of hydrogen and 1 gram of deuterium do not contain the same number of atoms. This is because hydrogen and deuterium have different atomic masses (1 amu for hydrogen and 2 amu for deuterium). Therefore, for a given mass, deuterium will have half the number of atoms as hydrogen. Also, hydrogen and deuterium are not isobars but isotopes.
Question 2: Which of the following elements has the same molecular mass as its atomic mass?
a) Nitrogen
b) Neon
c) Oxygen
d) Chlorine
Answer:
The correct answer is b) Neon.
Neon is a noble gas and exists as single atoms (Ne), so its atomic mass (approximately 20 amu) is the same as its molecular mass. Other elements like nitrogen (N₂), oxygen (O₂), and chlorine (Cl₂) exist as diatomic molecules and have molecular masses that are double their atomic masses.
Question 3: The atomic mass of sulfur is
a) 16
b) 31
c) 32
d) 15
Answer:
The correct answer is c) 32.
The atomic mass of sulfur is approximately 32 atomic mass units (u).
Question 4: Atomic mass of nitrogen is
a) 28 g
b) 28 u
c) 14 u
d) 14 g
Answer:
The correct answer is c) 14 u.
The atomic mass of nitrogen is 14 atomic mass units (u).
Question 5: Which of the following statements is correct?
a) Isobars belong to the same element
b) Isotones belong to the same element
c) Isotopes belong to the same element
d) None of these
Answer:
The correct answer is c) Isotopes belong to the same element.
Isotopes are atoms of the same element with the same atomic number but different mass numbers.
Question 6: Which property of an element is always a natural number?
a) Atomic weight
b) Mass number
c) Atomic number
d) Atomic volume
Answer:
The correct answer is b) Mass number.
Mass number (the total number of protons and neutrons in an atom) is always a natural number.
Question 7: The correct atomic masses (in u) for Sodium, Chlorine, Carbon, and Oxygen respectively are:
a) 23u, 35.5u, 12u, 16u
b) 21u, 35.5u, 4u, 8u
c) 25u, 33.5u, 8u, 16u
d) 19u, 13.5u, 2u, 12u
Answer:
The correct answer is a) 23u, 35.5u, 12u, 16u.
These are the atomic masses of Sodium (23u), Chlorine (35.5u), Carbon (12u), and Oxygen (16u).
Question 8: For calculating the molality or the mole fraction of solute, if the molarity is known, it is necessary to know the density of the solution.
a) Both (A) and (R) are true and (R) is the correct explanation of (A).
b) Both (A) and (R) are true, but (R) is not the correct explanation of (A).
c) (A) is true, but (R) is false.
d) Both (A) and (R) are false.
Answer:
The correct answer is b) Both (A) and (R) are true, but (R) is not the correct explanation of (A).
If the molarity is known, the density of the solution must also be known in order to calculate molality or the mole fraction of the solute. However, molarity and molality are different concepts, and knowing density helps relate them, but does not directly explain them.
Question 9: A particular element X can be found in three gaseous forms: mono-atomic, di-atomic, and tri-atomic. If the density of one of its forms at a pressure of 8.21 atm and 400 K is 18 gm/L, then what would be the atomic mass of the element?
a) 72
b) 24
c) 36
d) 144
Answer:
The correct answer is a) 72. Using the ideal gas equation, the atomic mass of the element can be calculated as 72 g/mol.
Question 10: The ratio of charge to mass would be greater for:
a) Proton
b) Electron
c) Neutron
d) Alpha particle
Answer:
The correct answer is b) Electron.
The charge of both the electron and proton is equal in magnitude, but the electron has a much smaller mass compared to the proton. Therefore, the charge-to-mass ratio is higher for the electron. The order of the charge-to-mass ratio is: Neutron < Alpha particle < Proton < Electron.
