MCQ Questions for Class 9 Science Chapter 4 Structure of the Atom

Solving the Structure of the Atom Multiple Choice Questions of Class 9 Science Chapter 4 MCQ can be of extreme help as you will be aware of all the concepts. These MCQ Questions on Structure of the Atom Class 9 with answers pave for a quick revision of the Chapter thereby helping you to enhance subject knowledge. Have a glance at the MCQ of Chapter 4 Science Class 9 and cross-check your answers during preparation.

Multiple Choice Questions

Question 1.
In 1906, J.J. Thomson was awarded the Nobel prize for his discovery of:
(a) Electron
(b) Proton
(c) Neutron
(d) Positron

Answer

Answer: (a) Electron


Question 2.
Who discovered the nucleus of an atom?
(a) J.J. Thomson
(b) Neils Bohr
(c) Rutherford
(d) J. Chadwick

Answer

Answer: (c) Rutherford


Question 3.
Who is known as the ‘Father of nuclear Physics’?
(a) J. J. Thomson
(b) E. Rutherford
(c) Neils Bohr
(d) J. Chadwick

Answer

Answer: (b) E. Rutherford


Question 4.
An atomic number of an element equals to what present in the nucleus of its atom?
(a) Protons
(b) Electrons
(c) Both of them
(d) None of them

Answer

Answer: (a) Protons


Question 5.
Rutherford’s alpha-particle scattering experiment was responsible for the discovery of:
(a) Atomic nucleus
(b) Electron
(c) Proton
(d) Neutron

Answer

Answer: (a) Atomic nucleus


Question 6.
Isotopes of an element have:
(a) the same physical properties
(b) different chemical properties
(c) different number of neutrons
(d) different atomic numbers

Answer

Answer: (c) different number of neutrons


Question 7.
Number of valence electrons in CP ion are:
(a) 16
(b) 8
(c) 17
(d) 18

Answer

Answer: (b) 8


Question 8.
Which one of the following is a correct electronic configuration of sodium?
(a) 2, 8
(b) 8, 2, 1
(c) 2, 1, 8
(d) 2, 8, 1

Answer

Answer: (d) 2, 8, 1


Question 9.
Who used the term ‘ATOM’ for the first time?
(a) Rutherford
(b) John Dalton
(c) Chadwick
(d) Bohr

Answer

Answer: (b) John Dalton


Question 10.
Which of the following are called nucleon?
(a) Protons
(b) Neutrons
(c) Electrons
(d) Both, Protons and Neutrons

Answer

Answer: (d) Both, Protons and Neutrons


Question 11.
Which of the following particles was discovered first?
(a) Neutron
(b) Electron
(c) Proton
(d) Meson

Answer

Answer: (b) Electron


Question 12.
Which of the following atom does not have the neutron?
(a) Carbon
(b) Nitrogen
(c) Hydrogen
(d) Helium

Answer

Answer: (c) Hydrogen


Question 13.
Who gave the name ‘Proton’ the positively charged particles of an atom?
(a) Chadwick
(b) Goldstein
(c) Rutherford
(d) John Dalton

Answer

Answer: (c) Rutherford


Question 14.
The maximum number of electrons in any shell of an atom is:
(a) n2
(b) 2n2
(c) (n – 1)2
(d) 3n2

Answer

Answer: (b) 2n2


Question 15.
Which of the following rays have the maximum penetration power?
(a) α-rays
(b) X-rays
(c) γ-rays
(d) Cathod rays

Answer

Answer: (c) γ-rays


Question 16.
Who gave the first model of the atom?
(a) J.J. Thomson
(b) Chadwick
(c) Goldstein
(d) Neils Bohr

Answer

Answer: (a) J.J. Thomson


Fill in the Blanks.

Question 17.
______ are atoms of the same element, which have different mass numbers.

Answer

Answer: Isotopes


Question 18.
_______ are atoms having the same mass number but different atomic numbers.

Answer

Answer: Isobars


Question 19.
Neutrons are present in the nucleus of all atoms, except ________

Answer

Answer: hydrogen


Question 20.
α-particles are doubly-charged _________ ions.

Answer

Answer: helium


Question 21.
Neutron was discovered by _______

Answer

Answer: Chadwick


Question 22.
The neutral particle in the nucleus of an atom is ________

Answer

Answer: neutron


Question 23.
Atomic number of sodium is _________

Answer

Answer: 11


Question 24.
The mass of an electron is about _________ times, the mass of a hydrogen atom.

Answer

Answer: \(\frac{1}{2000}\)


True/False.

Question 25.
Sir J.J. Thomson discovered the anode rays.

Answer

Answer: False


Question 26.
According to Rutherford, the positive charge of an atom is concentrated in its center.

Answer

Answer: True


Question 27.
Elements are defined by the number of protons they possess.

Answer

Answer: True


Question 28.
Valency is the combining capacity of an atom.

Answer

Answer: True


Question 29.
α-particles have a mass of 2u.

Answer

Answer: False


Question 30.
The mass of electrons is considered to be negligible and its charge is plus one.

Answer

Answer: False


Question 31.
According to Thomson, an atom consists of a positively charged sphere and the electrons are embedded in it.

Answer

Answer: True


Question 32.
The negative and positive charges are equal in magnitude. So, the atom as a whole is electrically neutral.

Answer

Answer: True


Match the Column.

Question 33.

AB
1. Discovery of Proton(i) Deuterium
2. Hydrogen(ii) 4
3. Valency of Magnesium(iii) Positive charge
4. Valency of Carbon(iv) He
5. Symbol of Helium(v) H
6. Symbol of Hydrogen(vi) 2
7. Electron(vii) E. Goldstein
8. Proton(viii) Negative charge
Answer

Answer:

AB
1. Discovery of Proton(vii) E. Goldstein
2. Hydrogen(i) Deuterium
3. Valency of Magnesium(vi) 2
4. Valency of Carbon(ii) 4
5. Symbol of Helium(iv) He
6. Symbol of Hydrogen(v) H
7. Electron(viii) Negative charge
8. Proton(iii) Positive charge

Answer in Word/Sentence.

Question 34.
What is the value of charge on a proton?

Answer

Answer: 1.6 × 10-19 coulomb positive charge


Question 35.
What is the value of charge on an electron?

Answer

Answer: 1.6 × 10-19 coulomb negative charge


Question 36.
What is the value of charge on a neutron?

Answer

Answer: Zero (0) or no charge


Question 37.
According to Neils Bohr, electrons can revolve only in certain orbits. What name was given by him to these certain orbits?

Answer

Answer: Discrete orbits of electrons


Question 38.
According to Bohr-Burry rules, which formula is used to express the maximum number of electrons in an orbit of an atom?

Answer

Answer: 2n2


Question 39.
What is the maximum number of electrons in the outermost shell, according to Bohr-Burry?

Answer

Answer: 8


 


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