Structure of the Atom Class 9 Case Study Questions Science Chapter 4

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Hello students, we are providing case study questions for class 9 science. Case study questions are the new question format that is introduced in CBSE board. The resources for case study questions are very less. So, to help students we have created chapterwise case study questions for class 9 science. In this article, you will find case study questions for cbse class 9 science chapter 4 Structure of the Atom.

Chapter	Structure of the Atom
Type of Questions	Case Study Questions
Nature of Questions	Competency Based Questions
Board	CBSE
Class	9
Subject	Science
Theme	Moving Things, People and Ideas
Useful for	Class 9 Studying Students
Answers provided	Yes
Difficulty level	Mentioned
Important Link	Class 9 Science Chapterwise Case Study

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Table of Contents

Case Study Questions on Structure of the Atom

Questions

Question 1:

Rutherford conducted the famous alpha particle scattering experiment by bombarding thin gold foil with positively charged alpha particles. Most particles passed through the foil undeflected, while a few were deflected at small angles and very few bounced back. This led to the conclusion that the atom is mostly empty space, the positive charge and mass are concentrated in a small nucleus, and electrons revolve around it.

Q1. What conclusion was drawn when most alpha particles passed straight through the gold foil?
(a) Atom is positively charged
(b) Atom has a large volume
(c) Atom has empty space
(d) Atom is neutral

Q2. What caused some alpha particles to deflect at small angles?
(a) Repulsion from electrons
(b) Attraction by neutrons
(c) Presence of empty space
(d) Repulsion from positively charged nucleus

Q3. Which part of the atom did Rutherford discover through this experiment?
(a) Neutron
(b) Proton
(c) Electron
(d) Nucleus

Q4. What is a major limitation of Rutherford’s model?
(a) It cannot explain atom’s mass
(b) It violates the laws of motion
(c) It could not explain stability of the atom
(d) It does not consider neutrons

Answers:
Q1. (c)
Q2. (d)
Q3. (d)
Q4. (c)

Question 2:

Niels Bohr modified Rutherford’s model by introducing the concept of fixed energy levels or shells. According to Bohr, electrons revolve in specific orbits without radiating energy. Each orbit or shell is associated with a definite energy and is denoted by letters K, L, M, N… The maximum number of electrons in a shell is given by the formula 2n², where n is the orbit number.

Q1. Which postulate of Bohr explains why electrons do not lose energy?
(a) Electrons are at rest
(b) Electrons do not revolve
(c) Electrons revolve in fixed energy levels
(d) Electrons gain energy from the nucleus

Q2. What is the maximum number of electrons that can be accommodated in the L shell?
(a) 2
(b) 8
(c) 18
(d) 32

Q3. Which rule determines electron capacity of a shell?
(a) n²
(b) 2n
(c) 2n²
(d) n + l

Q4. What was a key improvement in Bohr’s model over Rutherford’s?
(a) Inclusion of protons
(b) Stability of the atom explained
(c) Discovery of neutrons
(d) Electron mass calculation

Answers:
Q1. (c)
Q2. (b)
Q3. (c)
Q4. (b)

Question 3:

An atom has 4 electrons, 4 protons, and 4 neutrons. Electrons carry a negative charge, protons carry an equal but positive charge, and neutrons are neutral. The atom, in this case, has equal numbers of positively and negatively charged particles, making it electrically neutral. The presence of 4 protons also determines the atomic number of the element, while the mass number is the sum of protons and neutrons.

Use the information to answer the following questions:

Q1. What is the atomic number of this atom?
(a) 4
(b) 8
(c) 12
(d) 0

Q2. What is the mass number of this atom?
(a) 4
(b) 8
(c) 12
(d) 16

Q3. The atom is electrically neutral because:
(a) It contains more electrons than protons
(b) It contains more protons than electrons
(c) The number of electrons and protons are equal
(d) It has neutrons only

Q4. The element described in the passage is:
(a) Hydrogen
(b) Helium
(c) Beryllium
(d) Boron

Answers:
Q1. (a)
Q2. (b)
Q3. (c)
Q4. (c)

Also check

Case study questions for other chapters of class 9 science is given below.

We hope the given case study questions for Structure of the Atom Class 9 helps you in your learning.

Helpful Links for CBSE Class 9 Science Preparation

Topics from which case study questions may be asked

Discovery of Subatomic Particles
Thomson’s and Rutherford’s Atomic Models
Bohr’s Model of the Atom
Atomic Number, Mass Number, Isotopes, and Isobars
Electronic Configuration and Valency

Atoms and molecules are the fundamental building blocks of matter. Different kinds of atoms combine together in different ways to form different kinds of substances.

Various atomic models have been proposed to know about the arrangement of electrons and protons within an atom. These are: Thomson’s model, Rutherford’s model and Bohr’s model.

Rutherford selected gold foil because he wanted as thin a layer as possible.

For further practice on case study questions related to Structure of the Atom Class 9 Science, we recommend exploring the link given below.

Practice More Case Study Questions on “Structure of the Atom”

Frequently Asked Questions (FAQs) on Structure of the Atom Case Study Questions

Q1: What are case study questions for CBSE examinations?

A1: Case study questions in CBSE examinations typically involve scenarios or real-life examples, requiring students to apply their understanding of concepts to solve problems or analyze situations.

Q2: Why are case study questions important for understanding class 9 science chapters?

A2: Case study questions provide a practical context for students to apply theoretical knowledge to real-world situations, fostering deeper understanding and critical thinking skills.

Q3: How should students approach answering case study questions for CBSE?

A3: Students should carefully read the case study, identify the key issues or problems presented, analyze the information provided, apply relevant concepts and principles of chemical reactions and equations, and formulate well-supported solutions or responses.

Q4: Are there any resources available online for students to practice case study questions on class 9 science chapters for CBSE exams?

A4: Yes, several educational websites offer case study questions for CBSE students preparing for science examinations. We also offer a collection of case study questions for all classes and subject on our website. Visit our website to access these questions and enhance your learning experience. If you need more case study questions for your preparation, then you visit Physics Gurukul website.

Q5: How can students effectively prepare for case study questions on “Structure of the Atom” for CBSE exams?

A5: Effective preparation strategies include regular revision of concepts, solving practice questions, analyzing case studies from previous exams, seeking clarification on doubts, and consulting with teachers or peers for guidance and support.

Q6: How can teachers incorporate case study questions on “Structure of the Atom” class 9 science into classroom teaching?

A6: Teachers can integrate case studies into lesson plans, group discussions, or interactive activities to engage students in active learning, promote problem-solving skills, and facilitate a deeper understanding of “Structure of the Atom”.

Q7: Who discovered the nucleus of the atom?

A7: Ernest Rutherford discovered the nucleus of the atom by using alpha-ray scattering experiment.

Q8: Name the three sub-atomic particles of an atom.

A8: (a) Electron
(b) Proton and
(c) Neutron

Q9: Why is it not possible to see an atom with naked eyes?

A9: It is not possible to see an atom with naked eyes because it is very small in size. Atomic radius is measured in nanometer, 1 nm = 10^–9 m.

Q10: Define atomic number.

A10: The number of protons present in the nucleus of an atom is known as its atomic number. In a neutral atom, number of protons equal to the number of electrons. It is denoted by the symbol Z.

Q11: Define mass number.

A11: The total number of protons and neutrons in the nucleus of an atom is known as its mass number. It denoted by symbol A.

Q12: Which shell can accommodate a maximum of 32 electrons?

A12: N-shell accommodates a maximum of 32 electrons.

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