CBSE Class 11 Chemistry Structure Of Atom Worksheet Set A

Structure Of Atom MCQ Questions with Answers Class 11 Chemistry

Question- Which of the following does not contain number of neutrons equal to that of 40Ar 18 ?

(a) 41K
     19

(b) 43
     21Sc

(c) 40Sc
     21

(d) Ca 42
      20

Answer-(c)

Question-The radius of 1st Bohr’s orbit for hydrogen atom is ‘r’. The radius of second Bohr’s orbit is

(a) 4r

(b) r³

(c) 4r²

(d) r^1/3

Answer-(a)

Question-The number of electrons and neutrons of an element is 18 and 20 respectively. Its mass number is

(a) 2

(b) 17

(c) 37

(d) 38

Answer-(d)

Question- The ideal body, which emits and absorbs radiations of all frequencies, is called a black body and the radiation emitted by such a body is called

(a) white body radiation

(b) black body radiation

(c) black body emission

(d) None of these

Answer-(b)

Question-Nucleons are

(a) only neutrons

(b) neutrons + protons

(c) neutrons + protons + electrons

(d) neutrons + electrons

Answer-(b)

Question-Number of protons, neutrons and electrons in the element 89^{X 231} is

(a) 89, 89, 242

(b) 89, 142, 89

(c) 89, 71, 89

(d) 89, 231, 89

Answer-(b)

Question-Atoms with same mass number but different atomic numbers are called

(a) isotopes

(b) isobars

(c) isochores

(d) None of these

Answer-(b)

Question-An electron from one Bohr stationary orbit can go to next higher orbit

(a) by emission of electromagnetic radiation

(b) by absorption of any electromagnetic radiation

(c) by absorption of electromagnetic radiation of particular frequency

(d) without emission or absorption of electromagnetic radiation

Answer-(c)

Question-An element has atomic number 11 and mass number 24.What does the nucleus contain?

(a) 11 protons, 13 neutrons

(b) 11 protons, 13 neutrons, 13 electrons

(c) 13 protons, 11 neutrons

(d) 13 protons, 11 electrons

Answer-(a)

Question-What is the difference between two species if one has atomic mass = 14 and atomic number = 7 whereas the other has atomic mass = 14 and atomic number = 6 ?

(a) Neutrons

(b) Protons

(c) Electrons

(d) All of these

Answer-(d)

Question- When a metal surface is exposed to solar radiations

(a) The emitted electrons have energy less than a maximum value of energy depending upon frequency of incident radiations

(b) The emitted electrons have energy less than maximum value of energy depending upon intensity of incident radiation

(c) The emitted electrons have zero energy

(d) The emitted electrons have energy equal to energy of photons of incident light

Answer-(a)

Question-If the wavelength of the electromagnetic radiation is increased to thrice the digital value, then what will be the percent change in the value of frequency of the electromagnetic radiation.

(a) Increases by 33%

(b) Decreases by 33%

(c) Increases by 66%

(d) Decreases by 66%

Answer-(d)

Question- Which one of the following pairs is not correctly matched ?

(a) Rutherford-Proton

(b) J.J. Thomson-Electron

(c) J.H. Chadwick-Neutron

(d) Bohr-Isotopes

Answer-(d)

Question- From the data given below A, B, C and D respectively are,
(A) 10 e^–, atomic no. 11 (B) 10 e^–, atomic no. 6
(C) 10 e^–, atomic no. 10 (D) 10 e^–, atomic no. 9

(a) Na⁺, C^4–, Ne, F^–

(b) C^4–, Ne, Na^–, F^–

(c) F^–, Na⁺, Ne, C^4–

(d) F–, Na⁺, C^4–, Ne

Answer-(a)

Question-Which of the following is related with both wave nature and particle nature ?

(a) Interference

(b) E = mc²

(c) Diffraction

(d) E = hv

Answer-(d)

Question- ‘A’ represents mass no. and Z represents atomic no. then α - decay is characterized by

(a) Z increases by 2, A decreases by 4

(b) Z decreases by 2, A increases by 4

(c) Z decreases by 2, A decreases by 4

(d) Z increases by 2, A increases by 4.

Answer-(c)

Question- In the photo-electron emission, the energy of the emitted electron is

(a) greater than the incident photon

(b) same as than of the incident photon

(c) smaller than the incident photon

(d) proportional to the intensity of incident photon

Answer-(c)

Question- In Bohr’s model, atomic radius of the first orbit is y, the radius of the 3rd orbit, is

(a) y / 3

(b) y

(c) 3y

(d) 9y

Answer-(d)

Question-Which of the following statements do not form a part of Bohr’s model of hydrogen atom ?

(a) Energy of the electrons in the orbits are quantized

(b) The electron(s) in the orbit nearest to the nucleus has the lowest energy

(c) Electrons revolve in different orbits around the nucleus

(d) The position and velocity of the electrons in the orbit cannot be determined simultaneously

Answer-(d)

Question- Which one of the following is not the characteristic of Planck’s quantum theory of radiation ?

(a) The energy is not absorbed or emitted in whole number or multiple of quantum

(b) Radiation is associated with energy

(c) Radiation energy is not emitted or absorbed continuously but in the form of small packets called quanta

(d) This magnitude of energy associated with a quantum is proportional to the frequency.

Answer-(a)

Question- The third line of the Balmer series, in the emission spectrum of the hydrogen atom, is due to the transition from the

(a) fourth Bohr orbit to the first Bohr orbit

(b) fifth Bohr orbit to the second Bohr orbit

(c) sixth Bohr orbit to the third Bohr orbit

(d) seventh Bohr orbit to the third Bohr orbit

Answer-(b)

More Question

Instructions:1. All questions are compulsory.2. Please give the explanation for the answer where applicable.

Q1 - What were the discrepancies observed in Bohr’s model?

Q2 - How many protons and neutron are in the following nuclei? 

Q3 - Which of the following orbitals are not possible -

2 d, 4f, 6d, 3g 

Q4 - If the largest value of m for an electron is +2, then the electron may be present in what type of sub shell? 

Q5 - Point out the differences and similarities in the orbitals represented by following sets of quantum numbers- n l m

(i) 3 2 +2

(ii) 3 2 –1

Q6 - The work function of a metal is 4.2 eV. If radiations of 2000 A0 fall on the metal , then find the kinetic energy of fastest photon electron. 

Q7 - What is the value of Plank’s constant in S.I. Units? 

Q8 - When a ball is hit with a hockey stick by a player, it does not make a wave. Why? 

Q9 - Which series are produced when electrons from the outer orbits jumps to 3rd orbit? 

Please refer to the link below for CBSE Class 11 Chemistry Structure Of Atom Worksheet Set A