## Class 9 Science Objective Chapter – 4 Structure of the Atom

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

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

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

( 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?

( B ) Goldstein

( C ) Rutherford

( D ) John Dalton

Ans – ( C )

33. Who discovered the electron?

( A ) Rutherford

( 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

( 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 )