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Class 9 Science Chapter 4 Structure Of The Atom Quiz 3
Are you ready to test your knowledge of atomic structure with Class 9 Structure of the Atom quiz questions? Our Chapter 4 Atom structure quiz for Class 9 is designed to help you understand the fundamentals of atomic structure, preparing you for your exams in a fun and interactive way. This Structure of the Atom quiz 3 not only challenges you with various questions but also provides answers and explanations to strengthen your concepts.
The Class 9 Science atom structure quiz covers essential topics from Chapter 4, making it a great tool for both revision and self-assessment. With Chapter 4 quiz on structure of atoms, you can practice Structure of Atom MCQs quiz and improve your understanding of complex ideas like electrons, protons, and neutrons.
Taking this Science quiz on structure of atoms Class 9 gives you the opportunity to identify areas where you may need more focus. By solving the Quiz 3 Structure of the Atom Class 9 Science questions, you’ll be able to prepare more effectively for your exams.
This Class 9 Chapter 4 quiz on atomic structure is a crucial step in mastering the concepts and preparing confidently for your tests. Whether you’re looking for Class 9 Science quiz atom structure preparation or simply want to revise with Chapter 4 Class 9 quiz 3 solutions, this quiz is an excellent resource. Dive into the Science Class 9 atom structure quiz questions and answers, and see how well you know your atoms.
Class 9 Chemistry Chapter 4 Structure Of The Atom Quiz 3 Questions
Question 1: What is atomic mass unit?
a) Mass of 1 atom of carbon-12
b) 1/8th mass of 1 atom of carbon-12
c) 1/10th mass of 1 atom of carbon-12
d) 1/12th mass of 1 atom of carbon-12
Answer:
The correct answer is d) 1/12th mass of 1 atom of carbon-12.
One atomic mass unit (amu) is defined as 1/12th the mass of 1 atom of carbon-12, which is taken as a reference. The atomic mass unit is symbolized as “amu” and is equal to the average mass of a proton and a neutron. 1 amu = 1.67377 × 10-27 kg or 1.67377 × 10-24 g.
Question 2: The total mass of one atom of any given element is called ____________.
a) atomic mass
b) molecular mass
c) molar mass
d) mole
Answer:
The correct answer is a) atomic mass.
Atomic mass refers to the total mass of one atom of a given element, and it is measured in unified atomic mass units (denoted by ‘u’).
Question 3: The unit of atomic mass is called the ____________.
a) atomic unit
b) mass
c) unit mass
d) unified atomic mass unit
Answer:
The correct answer is d) unified atomic mass unit.
The atomic mass unit (amu) is now known as the unified atomic mass unit (denoted by ‘u’) and represents the mass of atoms relative to 1/12th of the mass of a carbon-12 atom.
Question 4: Unified atomic mass unit is denoted by __________.
a) a
b) am
c) u
d) m
Answer:
The correct answer is c) u.
The unified atomic mass unit is represented by the symbol ‘u’. It is equal to 1/12th of the mass of a carbon-12 atom.
Question 5: One atomic mass unit is equal to exactly one-twelfth (1/12th) the mass of one atom of __________.
a) Nitrogen-14
b) Silicon-14
c) Carbon-14
d) Carbon-12
Answer:
The correct answer is
d) Carbon-12. The isotope Carbon-12 is the standard reference used to measure atomic masses. One atomic mass unit is 1/12th the mass of a carbon-12 atom.
Question 6: Is it true that the total mass of one atom of any given element is known as the atomic number?
a) True
b) False
Answer:
The correct answer is b) False.
The total mass of one atom of an element is called the atomic mass, not the atomic number. The atomic number refers to the number of protons in an atom.
Question 7: Atomic mass of an element is:
a) the actual mass of one atom of the element
b) the relative mass of one atom of the element
c) the average relative mass of different atoms of the element
d) much different from the mass number of the element
Answer:
The correct answer is c) the average relative mass of different atoms of the element.
Atomic mass is the weighted average of the masses of the isotopes of an element, which can result in a non-whole number.
Question 8: The atomic masses of elements are usually fractional because:
a) Elements consist of impurities
b) These are mixtures of allotropes
c) These are mixtures of isobars
d) These are mixtures of isotopes
Answer:
The correct answer is d) These are mixtures of isotopes.
Atomic masses are fractional because elements are usually composed of different isotopes, and the atomic mass is the average of their masses.
Question 9: Which of the following always exists as a whole number?
a) Atomic weight
b) Atomic number
c) Atomic radii
d) Equivalent weight
Answer:
The correct answer is b) Atomic number.
The atomic number, representing the number of protons in an atom, is always a whole number.
Question 10: Recently the unit of atomic mass amu was replaced by __________.
a) u
b) mol
c) g
d) kg
Answer:
The correct answer is a) u.
The atomic mass unit (amu) has been replaced by the unified atomic mass unit (denoted by ‘u’).