Here we are providing Class 9 Science Objective Chapter – 4 Structure of the Atom because its very important for Class 9 students as we all know that every board exam question has MCQs so that students should practice these questions so that students can get good marks in board. Class 9 Science Objective Chapter – 4 Structure of the Atom is an extremely important and its also a year in which students learn the fundamentals of concepts that help them lay a solid foundation for their higher education. Here we are providing in Class Class 9 Science Objective Chapter – 4 Structure of the Atom 100+ questions so that students practice more and more. If you want class wise Notes Then Click Here
Class 9 Science Objective Chapter – 4 Structure of the Atom
1.In 1906, J.J. Thomson was awarded the Nobel prize for his discovery of:
( A ) Electron
( B ) Proton
( C ) Neutron
( D ) Positron
Ans – ( A )
2.Which of the following correctly represents the electronic distribution in the Mg atom?
( A ) 3, 8, 1
( B ) 2, 8, 2
( C ) 1, 8, 3
( D ) 8, 2, 2
Ans – ( B )
3. The number of electrons in an atom of Fluorine is 9. Its electronic configuration is
( A ) 8, 1
( B ) 7, 2
( C ) 2, 7
( D ) 1, 8
Ans – ( C )
4.The number of electrons in an element X is 15 and the number of neutrons is 16. Which of the following is the correct representation of the element?
( A ) 3115X
( B ) 3116X
( C ) 1615X
( D ) 1516X
Ans – ( A )
5.Who discovered the nucleus of an atom?
( A ) J.J. Thomson
( B ) Neils Bohr
( C ) Rutherford
( D ) J. Chadwick
Ans – ( C )
6.Which of the following are true for an element?
( A ) Atomic number = number of protons + number of electrons
( B ) Mass number = number of protons + number of neutrons
( C ) Atomic mass = number of protons = number of neutrons
( D ) Atomic number = number of protons = number of electrons
( A ) ( A ) and (ii)
( B ) ( A ) and (iii)
( C ) ( B ) and (iii)
( D ) ( B ) and (iv)
Ans – ( D )
7. Rutherford’s ‘alpha (α) particles scattering experiment’ resulted in the discovery of
( A ) electron
( B ) proton
( C ) nucleus in the atom
( D ) atomic mass
Ans – ( C )
8.Who is known as the ‘Father of nuclear Physics’?
( A ) J. J. Thomson
( B ) E. Rutherford
( C ) Neils Bohr
( D ) J. Chadwick
Ans – ( B )
9.Atomic models have been improved over the years. Arrange the following atomic models in the order of their chronological order
( A ) Rutherford’s atomic model
( B ) Thomson’s atomic model
( B ) Bohr’s atomic model
( A ) (i), ( B ) and (iii)
( B ) (ii), ( C ) and (i)
( C ) (ii), ( A ) and (iii)
( D ) (iii), ( B ) and (i)
Ans – ( C )
10. The valence electrons of an element are reponsible for
( A ) Physical properties of an element
( B ) Chemical properties of an element
( C ) Both the properties
( D ) None of these
Ans – ( B )
11.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
Ans – ( A )
12. Which isotope is used in the nuclear power plants to generate electricity?
( A ) Uranium 235
( B ) Iodine 131
( C ) Cobalt 60
( D ) Uranium 238
Ans – ( A )
13.Rutherford’s alpha-particle scattering experiment was responsible for the discovery of:
( A ) Atomic nucleus
( B ) Electron
( C ) Proton
( D ) Neutron
Ans – ( A )
14. Nucleous consist of:
( A ) Proton and electron
( B ) Proton and neutron
( C ) Neutron and electron
( D ) Only neutron
Ans – ( B )
15.Isotopes of an element have:
( A ) the same physical properties
( B ) different chemical properties
( C ) different number of neutrons
( D ) different atomic numbers
Ans – ( C )
16. 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
Ans – ( B )
17.Number of valence electrons in CP ion are:
( A ) 16
( B ) 8
( C ) 17
( D ) 18
Ans – ( B )
18. Cathode rays have
( A ) Mass only
( B ) Charge only
( C ) Both mass and charge
( D ) Neither mass nor charge
Ans – ( C )
19.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
Ans – ( D )
20. What was the source of alpha particles in Rutherford scattering experiment?
( A ) Hydrogen nucleus
( B ) Argon nucleus
( C ) Helium nucleus
( D ) None of these
Ans – ( C )
21.Who used the term ‘ATOM’ for the first time?
( A ) Rutherford
( B ) John Dalton
( C ) Chadwick
( D ) Bohr
Ans – ( B )
22. 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
Ans – ( A )
23.Which of the following are called nucleon?
( A ) Protons
( B ) Neutrons
( C ) Electrons
( D ) Both, Protons and Neutrons
Ans – ( D )
24. If Z = 6, what would be the valency of the element?
( A ) 6
( B ) 2
( C ) 4
( D ) 8
Ans – ( C )
25.An atom with 3 protons and 4 neutrons will have a valency of
( A ) 3
( B ) 7
( C ) 1
( D ) 4
Ans – ( C )
26.Which of the following particles was discovered first?
( A ) Neutron
( B ) Electron
( C ) Proton
( D ) Meson
Ans – ( B )
27. Electron is represented as ……….
( A ) El
( B ) E
( C ) e
( D ) none of the above
Ans – ( C )
28. The first model of an atom was given by
( A ) N. Bohr
( B ) E. Goldstein
( C ) Rutherford
( D ) J.J. Thomson
Ans – ( D )
29. Ions containing positive charge called…………
( A ) Positive charge
( B ) Positive ion
( C ) Proton
( D ) Photon
Ans – ( C )
30.Which of the following atom does not have the neutron?
( A ) Carbon
( B ) Nitrogen
( C ) Hydrogen
( D ) Helium
Ans – ( C )
31. The nucleus of the hydrogen atom is called as
( A ) Neutron
( B ) Electron
( C ) Proton
( D ) Nucleons
Ans – ( C )
32.Who gave the name ‘Proton’ the positively charged particles of an atom?
( A ) Chadwick
( B ) Goldstein
( C ) Rutherford
( D ) John Dalton
Ans – ( C )
33. Who discovered the electron?
( A ) Rutherford
( B ) Chadwick
( C ) Thomson
( D ) Goldstein
Ans – ( C )
34. Which of the following does not match the characteristics of an Isotope?
( A ) Isotopes of some elements are radioactive
( B ) Isotopes are the atoms of different elements
( C ) Isotopes differ in number of neutrons
( D ) Isotopes have similar chemical properties
Ans – ( B )
35.The maximum number of electrons in any shell of an atom is:
( A ) n2
( B ) 2n2
( C ) (n – 1)2
( D ) 3n2
Ans – ( B )
36. 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
Ans – ( B )
37.Which of the following rays have the maximum penetration power?
( A ) α-rays
( B ) X-rays
( C ) γ-rays
( D ) Cathod rays
Ans – ( C )
38. An neutral element A has 3 electrons, the atomic number of an element is
( A ) 1
( B ) 2
( C ) 5
( D ) 3
Ans – ( D )
39.Who gave the first model of the atom?
( A ) J.J. Thomson
( B ) Chadwick
( C ) Goldstein
( D ) Neils Bohr
Ans – ( D )
40. 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.
Ans – ( A )