MCQ Class 9 Science Chapter 4 Structure Of The Atom

Please refer to the MCQ Questions for Class 9 Science Chapter 4 Structure Of The Atom. The following Structure Of The Atom Class 9 Science MCQ Questions have been designed based on the latest syllabus and examination pattern for Class 9. Our experts have designed MCQ Questions for Class 9 Science with Answers for all chapters in your NCERT Class 9 Science book.

Structure Of The Atom Class 9 MCQ Questions with Answers

See below Structure Of The Atom Class 9 Science MCQ Questions, solve the questions and compare your answers with the solutions provided below.

Question. The subatomic particle called electron was discovered by : 
(a) J.J. Thomson
(b) Neils Bohr
(c) James Chadwick
(d) E. Goldstein

Question. Which of the following represents the correct electron distribution in magnesium ion ? 
(a) 2, 8
(b) 2, 8, 1
(c) 2, 8, 2
(d) 2, 8, 3

Question. Rutherford’s alpha particle scattering experiment led to the discovery of :     
(a) Nucleus
(b) Electrons
(c) Protons
(d) Neutrons

Question. The particle not present in an ordinary hydrogen atom is :     
(a) proton
(b) neutron
(c) nucleus
(d) electron

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

Question. The correct electronic configuration of a chloride ion is :       
(a) 2, 8
(b) 2, 8, 4
(c) 2, 8, 8
(d) 2, 8, 7

Question. The first model of an atom was given by :     
(a) Neils Bohr
(b) Ernest Rutherford
(c) J.J. Thomson
(d) Eugen Goldstein

Question. Goldstein’s experiments which involved passing high voltage electricity through gases at very low pressure resulted in the discovery of :   
(a) electron
(b) proton
(c) nucleus
(b) neutron

Question. Which of the following statement is always correct ?       
(a) an atom has equal number of electrons and protons
(b) an atom has equal number of electrons and neutrons
(c) an atom has equal number of protons and neutrons
(d) an atom has equal number of electrons, protons and neutrons

Question. The number of electrons in the atom of an element X is 15 and the number of neutrons is 16. Which of the following is the correct representation of an atom of this element ?   
(a) 31/15X
(b) 31/16X
(c) 16/15X
(d) 15/16X

Question. The ion of an element has 3 positive charges. The mass number of atom of this element is 27 and the number of neutrons is 14. What is the number of electrons in the ion ?       
(a) 13
(b) 10
(c) 14
(d) 16

Question. What is the maximum number of electrons which can be accommodated in the :
(a) innermost shell of an atom ?
(b) outermost shell of an atom ?

Question. Which part of an atom was discovered by Rutherford’s alpha particle scattering experiment ?

Question. Which subatomic particle is not present in an ordinary hydrogen atom ?

Question. State the number of electrons present in the outermost shell of the atoms of the following elements :
(i) Neon (ii) Chlorine 

Question. State whether the following statements are true or false :
(a) Thomson proposed that the nucleus of an atom contains protons and neutrons.
(b) The cathode rays obtained from all the gases consist of negatively charged particles called electrons.
(c) The anode rays obtained from all the gases consist of positively charged particles called protons.

Question. Name the gas which produces anode rays consisting of protons in the discharge tube experiment.

Question. Fill in the blanks in the following statements :

Question The electron has ………………charge, the proton has …………….. charge, and the neutron has ………….. charge

Question The number of protons in the nucleus of an atom is called its ……….

Question An atom of an element has 11 protons, 11 electrons and 12 neutrons. The atomic mass of the atom is …………..

Question If the nucleus of an atom has atomic number 17, mass number 37 and there are 17 electrons outside the nucleus, the number of neutrons in it is ……….

Question The total number of protons and neutrons in the nucleus of an atom is called its ……….

Question An atom has atomic mass number 23 and atomic number 11. The atom has ………. electrons.

Question The anode rays obtained from hydrogen gas consist of particles called …………

Question The maximum number of electrons that can be accommodated in L shell are ……….

Question Almost all the mass of an atom is concentrated in a small region of space called the ………… .

Question Cathode rays are a beam of fast moving ……………

Question The maximum number of electrons that can go into the M shell is ……….

Question The subatomic particle not present in a hydrogen atom is …………..

Question: In a sample of ethyl ethanoate (CH₃COOC₂H₅) the two oxygen atoms have the same number of electrons but different number of neutrons.
Which of the following is the correct reason for it?
(a) One of the oxygen atoms has gained electrons.
(b) One of the oxygen atoms has gained two neutrons.
(c) The two oxygen atoms are isotopes.
(d) The two oxygen atoms are isobars.   

Question: Which pair of molecules has the same number of electrons?
(a) N₂ and F₂
(b) Cl₂ and CO₂
(c) H₂O and H₂S
(d) O₂ and C₂H₄   

Question: The table given below shows the numbers of protons, neutrons and electrons in four ions.
For which ion is the data correct? 

Question: An atom with 3 protons and 4 neutrons will have a valency of
(a) 3
(b) 7
(c) 1
(d) 4 

Question: Atomic models have been improved over the years. Arrange the following atomic models in the order of their chronological order 
(i) Rutherford’s atomic model
(ii) Thomson’s atomic model
(iii) Bohr’s atomic model
(a) (i), (ii) and (iii)
(b) (ii), (iii) and (i)
(c) (ii), (i) and (iii)
(d) (iii), (ii) and (i) 

Question: The electron distribution in an aluminium atom is
(a) 2, 8, 3
(b) 2, 8, 2
(c) 8, 2, 3
(d) 2, 3, 8

Question: Select the correct statements.
(i) An atom is divisible and consists of charged particles.
(ii) It was known by 1900 that the atom was not a simple, indivisible particle but contained at least one sub-atomic particle – the electron.
(iii) E. Goldstein in 1886 discovered the presence of new radiations called canal rays which led to the discovery of another sub-atomic
particle – the proton.
(iv) Proton had a charge, equal in magnitude but opposite in sign to that of the electron and its mass was approximately 2000 times as that of the electron.
(v) The mass of an electron is considered to be negligible and its charge is minus one.
(a) (i), (ii) and (iii)
(b) (iii), (iv) and (v)
(c) (ii), (iii) and (iv)
(d) All the statements are correct. 

Question: The schematic atomic structures of three elements X, Y and Z are given as:

Which of the following statements are incorrect?
I. Z can form ZCl₃ and ZCl₅.
II. Y exists in monatomic form.
III. X and Z combine to form X₃Z type compound.
IV. X and Y combine to form XY₂ type compound.
V. X will gain two electrons to form a stable compound.
(a) I and II
(b) I, II and IV
(c) II, IV and V
(d) III, IV and V 

Question: The ion of an element has 3 positive charges.
Mass number of the atom is 27 and the number of neutrons is 14. What is the number of electrons in the ion?
(a) 13
(b) 10
(c) 14
(d) 16   

Question: The electronic configuration of elements A, B, C and D are (2, 8, 1), (2, 8, 2), (2, 8, 6) and (2, 8, 7) respectively. Which of them can make an ion with two negative charges?
(a) A
(b) B
(c) C
(d) D 

Question: Which of the following do not represent Bohr’s model of an atom correctly?

(a) (i) and (ii)
(b) (ii) and (iii)
(c) (ii) and (iv)
(d) (i) and (iv) 

Question: The nucleon number of the bromine atom is 79 and its proton number is 35. Which of the following is true about the bromine atom?
(a) It has 79 neutrons.
(b) It has 44 electrons.
(c) Its electronic configuration contains three shells which has 7 electrons in outermost shell.
(d) It has similar chemical properties as chlorine.

Question: Match the column I with column II and select the correct answer by choosing an appropriate option.
    Column I                                     Column II
P. Mass of proton                           1. 9.1 × 10–28 g
Q. Charge of electron                     2. 1.6 × 10–19 C
R. Mass of electron                        3. –1.6 × 10–19 C
S. Charge on proton                      4. 1.67 × 10–27 kg
(a) P – 4, Q – 3, R – 1, S – 2
(b) P – 2, Q – 1, R – 4, S – 3
(c) P – 2, Q – 3, R – 4, S – 1
(d) P – 4, Q – 2, R – 1, S – 3 

Question: Dalton’s atomic theory successfully explained (i) law of conservation of mass (ii) law of constant composition
(iii) law of radioactivity
(iv) law of multiple proportion.
(a) (i), (ii) and (iii)
(b) (i), (iii) and (iv)
(c) (ii), (iii) and (iv)
(d) (i), (ii) and (iv) 

Question: Th given table shows the number of protons, neutrons and electrons in atoms or ions. Which atom/ion in the table is an isotope of the atom with the composition of 11p, 11e and 14n? IMAGE 15
(a) P
(b) Q
(c) R
(d) S   

Question: Which of the following has the same number of electrons as an oxide ion (O^2–)?
(a) K+
(b) Mg²+
(c) Cl–
(d) S^2–

Question: Which of the following is an accurate illustration of a nitrogen atom?

Question: A monovalent anion has 10 electrons and 10 neutrons. The atomic number and mass number of the element are respectively ______ and _____.
(a) 10, 20
(b) 9, 18
(c) 11, 20
(d) 9, 19   

Question: Observe the given figure and answer the question that follows :

(I) Most of the fast moving α-particles passed straight through the gold foil.
(II) Some of the α-particles were deflected by the foil by small angles.
(III) Surprisingly one out of every 12000 particles appeared to rebound.
Identify the correct observations.
(a) (I) and (II)
(b) (II) and (III)
(c) (I) and (III)
(d) All are correct.

Question: Vivek was given few models of atoms representing their structures. He was asked to choose one pair of isotopes and one pair of isobars.

Which of the following options contains the correct pairs?
Isotopes                                   Isobars
(a) (i) and (ii)                          (iii) and (iv)
(b) (i) and (iv)                         (ii) and (iii)
(c) (i) and (iii)                         (ii) and (iv)
(d) (ii) and (iv)                        (i) and (iii) 

Question: Mass spectrum of lead is given as The average atomic mass of lead is 

(a) 208
(b) 207.567
(c) 207.302
(d) 209   

Question: Two particles X and Y have the composition as shown in the table.31 IMAGE
The particles X and Y are
(a) metal atoms
(b) non-metal atoms
(c) negative ions
(d) positive ions.   

Question: An element L has 9 protons and its valency is 1. Another element M has valency 3 and 5.
What is the difference in the number of electrons in L and M?
(a) 6
(b) 5
(c) 4
(d) 3 

Question: In the Thomson’s model of atom, which of the following statements are correct?
(i) The mass of the atom is assumed to be uniformly distributed over the atom.
(ii) The positive charge is assumed to be uniformly distributed over the atom.
(iii) The electrons are uniformly distributed in the positively charged sphere.
(iv) The electrons attract each other to stabilise the atom.
(a) (i), (ii) and (iii)
(b) (i) and (iii)
(c) (i) and (iv)
(d) (i), (iii) and (iv)   

Question: Information about two atoms, X and Y are shown below :

Which of the following is correct about these two atoms?
                                               Atom X     Atom Y
(a) Electronic                             2, 8, 4       2, 8, 5
   configuration :
                                                                 
(b) Number of                             7                7
    neutrons :

(c) Number of valence                 5                 5
      electrons :

(d) Number of electron              2                  3  C
        shells :

Question: The relative atomic mass of naturally occurring chlorine is not a whole number. What is the reason for this?
(a) Chlorine atoms can have different numbers of neutrons.
(b) Naturally occurring chlorine cannot be obtained pure.
(c) Chlorine is unstable.
(d) The mass of the electrons has been included. 

Question: Match the column I with column II and select the correct answer by choosing an appropriate option.
Column I                                  Column II
P. Neutron                               1. Rutherford’s
                                                    atomic model
Q. Plum pudding model            2. Bohr’s atomic
                                                   model
R. Mass of the atom is             3. Thomson’s atomic
concentrated at the                       model
centre of atom
S. Stationary orbit 4. Chadwick
(a) P – 1, 4; Q – 1, 2, 3; R – 2; S – 1, 2, 3
(b) P – 1; Q – 1, 2, 3; R – 2; S – 1, 2
(c) P – 1; Q – 3; R – 2; S – 1
(d) P – 4; Q – 3; R – 1; S – 2 

Question: Rutherford concluded from the a-particle scattering experiment that
(i) most of the space inside the atom is empty because most of the α-particles passed through the gold foil without getting deflected.
(ii) very few particles were deflected from their path, indicating that the negative charge of the atom occupies very little space.
(iii) a very large fraction of α-particles were deflected by 180°°, indicating that all the negative charge and mass of the gold atom were not concentrated in a very small volume within the atom.
Identify the incorrect statements.
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (i) and (iii)
(d) (i), (ii) and (iii) 

Question: The main drawback of Rutherford’s model of the atom is that
(a) it does not explain the stability of atom
(b) it does not show the location of protons
(c) it does not explain neutral nature of an atom
(d) it does not explain existence of a nucleus in an atom.   

Question: Which pair of atoms contains the same number of neutrons?

Question: Schematic atomic structures of three elements are given below :

Which of the following is the correct formula of the compound formed by the given three elements?
(a) Na₃PO₄
(b) Na₂CO₃
(c) Na₂SO₄
(d) Na₂SO₃   

Question: Study the table carefully and select the correct statement.

(a) W is a noble gas.
(b) X and Y are cations.
(c) U and V are anions. 
(d) Z is the lightest element while V is the heaviest. 

Question: Select the correct statements.
(i) The radius of the nucleus is about 107 times less than the radius of the atom.
(ii) There is a positively charged centre in an atom called the nucleus. Nearly all the mass of an atom resides in the nucleus.
(iii) The electrons revolve around the nucleus in circular paths.
(iv) The size of the nucleus is very large as compared to the size of the atom.
(a) (i) and (iv)
(b) (ii) and (iii)
(c) (i), (ii) and (iii)
(d) All the statements are correct. 

Question: Match the following:-
  List-I                                        List-II
(P) Proton                               1. Thomson
(Q) Electron                            2. Goldstein
(R) Neutron                            3. Rutherford
(S) Nucleus                             4. Chadwick
(a) P-4, Q-3, R-2, S-1
(b) P-1, Q-2, R-3, S-4
(c) P-2, Q-1, R-4, S-3
(d) P-2, Q-1, R-3, S-4 

Question: A has 9 protons, 9 electrons and 10 neutrons,B has 12 protons, 12 electrons and 12 neutrons.
Formula of the compound between A and B is
(a) BA₂
(b) AB₂
(c) B₂ A₃
(d) AB₄ 

Question: Match the following:-
      List-I                                       List-II
(P) Electrons                        1. Number of positively
                                          charged particles innucleus
(Q) Carbon dating                2. Negatively charged
particles
(R) Valence electrons           3. Technique to know
age of fossils
(S) Atomic number              4. Number of electrons
in outermost shell
(a) P-1, Q-2, R-3, S-4 
(b) P-4, Q-3, R-2, S-1
(c) P-2, Q-4, R-3, S-1
(d) P-2, Q-3, R-4, S-1 

Question: Which one of the following is not isoelectronic with neon atom?
(a) 😯^2–
(b) ₁₁Na⁺
(c) 9F^–
(d) 12Mg⁺