chapter atomic structure MCQs

 

CHAPTER 4

ATOMIC STRUCTURE

Q.1. Color of the glow produced in the discharge tube

a. depends on the pressure in the discharge tube

b. depends on the metal used as cathode

c. depends on the gas used in the discharge tube

d. does not depend on the nature of the gas used in the discharge tube

(c)

 

Q. 2. Dr. Khan told his students that if charge on electrons in a chamber is 3.50 x 10 11 coulomb than mass of electrons must be

a. 9.1 x 10-31 kg

b. 8 kg

c. 4 kg

d. 2 kg

(d)

 

Q. 3. e/m ratio of the canal rays is less than that of cathode rays. The reason is

a. greater mass of canal ray particles

b. greater charge of the canal ray particles

c. greater mass and charge of the canal ray particles

d. actually e/m ratio of canal rays is greater than that of the cathode rays

(a)

 

Q. 4. Nuclear radiation is emitted by those elements whose

a. molecules are stable

b. molecules are unstable

c. nuclei are stable

d. nuclei are unstable

(d)

 

Q. 5. -rays are good ionizers of gases because they

a. have greater mass

b. have positive charge

c. have greater mass and positive charge

d. are helium nuclei

(c)

 

Q. 6. Consider the following reaction Be + He C + n

This reaction is

a. a chemical reaction

b. a nuclear reaction

c. an example of artificial radioactivity

d. an exothermic reaction

(c)

 

Q. 7. Roentgen discovered X-rays and Mosley found that the frequency of the X-rays emitted from anode increases with the

a. increase in the mass number of the metal used as anode

b. decrease in the mass number of the metal used as anode

c. decrease in the proton number of the metal used as anode

d. increase in the proton number of the metal used as anode

(d)

 

Q. 8. Radiation emitted by exited atoms is

a. in the form of continuous waves

b. in the form of quanta

c. nuclear radiations

d. ultraviolet radiation

(b)

 

Q. 9. If the electron of hydrogen atom jumps of “M” shell then the radius of this excited hydrogen

atom will be

a. 8.464 Ao

b. 4.761 Ao

c. 2.116 Ao

d. 0.529 Ao

(b)

 

Q. 10. If a particle of mass 0.1gram moves with a velocity of 10,000 m/s then the wavelength of the wave associated with this particle is

a. 6.626 x 10-34 m

b. 2.145 x 10-39 m

c. 3.313 x 10-21 m

d. 1.325 x 10-18 m

(a)

 

Q. 11. Second ionization energy

a. is always less than first ionization energy

b. is always greater than first ionization energy

c. is equal to the first ionization energy

d. may be greater or less than the first ionization energy depending on the nature of the

element

(b)

 

Q. 12. “Ionization energies of the elements of the 5th group are greater than those of 6th group”. It is because

a. 5th group elements have less electronegativity

b. 6th group of elements have greater shielding effect

c. 5th group element have greater shielding effect

d. 5th group elements have half filled atomic orbitals

(d)

 

Q. 13. A sodium lamp emits yellow light with a wavelength of 589 nm. What is the energy of a

single photon in this light?

a. 3.37 x 10-19 Joules

b. 1.12 x 10-25 Joules

c. 1.17 x 10-33 Joules

d. 5.09 x 1015 Joules

(a)

 

Q. 14. The energy associated with the transition of an electron from the n=1 state to the n=3 state of H atoms is:

a. +1.74 x 10-17 Joules

b. +1.94 x 10-18 Joules

c. +1.94 x 10-18 Joules

d. -1.74 x 10-17 Joules

(b)

 

Q. 15. All of the following are electromagnetic radiations except

a. red light

b. sound waves

c. x-rays

d. photon

(b)

Q. 16. This shape of a 2s orbital resembles:

a. a hockey puck

b. an (American) football

c. an ellipse

d. a sphere

(d)

 

Q. 17. Which orbital of the following has a principal quantum number of 3 and an angular

momentum quantum number of 27

a. 3s

b. 3d

c. 4f

d. 3f

(b)

 

Q. 18. Which of the following has the highest energy?

a. gamma rays

b. X-rays

c. Ultra-violet radiation

d. radio waves

(a)

 

Q. 19. All of the following elements are correct for atomic orbitals except

a. p-sub energy level has 3 orbitals

b. s-orbital has spherical shape

c. energy of 4s is less than that of 4d

d. All d orbitals have 4 lobes

(d)

 

Q. 20. Various values of the quantum numbers (n, /, m, ms) are listed below. Which is a possible

set of values for one of the d electrons in an iron atom in its ground state?

a. (1, 1, 0, ½)

b. (4, 0, 1, ½)

c. (4, 1, 0, -1/2)

d. (3, 2, 1, -1/2)

(d)

 

Q. 21. How many orbitals are allowed for principal quantum number (n) of 3?

a. 9

b. 8

c. 6

d. 4

(a)

 

Q. 22. Which of the following orbitals are degenerate in a multielectron atom?

a. 3d orbitals

b. 3s, 3p, 3d orbitals

c. 1s, 2s orbitals

d. 2d orbitals

(a)

 

Q. 23. The quantum number that specifies the way the orbital is oriented in space is:

a. the electron spin quantum number

b. the magnetic quantum number

c. the angular momentum quantum number

d. the principal quantum number

(b)

 

Q. 24. Which of the following has the largest wavelength?

a. visible light

b. x-rays

c. infrared light

d. ultraviolet radiation

(c)

 

Q. 25. Select the arrangement of electromagnetic radiation which starts with the lowest energy

and increases to greatest energy.

a. radio, visible, infrared, visible, ultraviolet

b. microwave, infrared, visible, ultraviolet

c. visible, ultraviolet, infrared, gamma rays

d. X-radiation, visible, infrared, microwave

(b)

 

Q. 26. A radio station broadcasts music at 99.1 MHz. The wavelength of these waves is

a. 1.88 x 10-2 m

b. 0.330 m

c. 3.03 m

d. 5.33 x 102 m

(c)

 

Q. 27. Green light has a wavelength of 5200A. Calculate the energy of one photon of green light.

a. 3.4 x 10-40 J

b. 3.4 x 10-30 J

c. 3.8 x 10-26 J

d. 3.8 x 10-19 J

(d)

 

Q. 28. The size of an atomic orbital is associated with

a. principal quantum number (n)

b. angular momentum quantum number (I)

c. magnetic quantum number (mI)

d. spin quantum number (ms)

(a)

 

Q. 29. Which of the following is a correct set of quantum numbers for an electron in a 5f orbital?

a. n = 5, I = 3, mI = +1

b. n = 5, I = 2, mI = +3

c. n = 4, I = 3, mI = 0

d. n = 4, I = 2, mI = +1

(a)

Q. 30. In the quantum mechanical treatment of the hydrogen atom, which one of the following

combinations of quantum numbers is not allowd?

a. 3, 1, -1

b. 3, 2, 2

c. 3, 2, -1

d. 3, 3, 2

(d)

 

Q. 31. “Each electron in an atom must have its own unique set of quantum numbers” is a

statement of

a. Aufbau principle

b. Pauli exclusion principle

c. Hund’s rule

d. Periodic law

(b)

 

Q. 32. The effective nuclear charge for an atom is less than the actual nuclear charge due to

a. Shielding

b. Penetration

c. Paramagnetism

d. Electron-pair repulsion

(a)

 

Q. 33. “Electrons added to atomic orbitals of the same energy will remain unpaired with parallel

spins until the subshell is more than half-filled” is a statement of

a. Aufbau principle

b. Pauli exclusion principle

c. Hund’s rule

d. Periodic law

(c)

 

Q. 34. All of the following statements are correct for atomic structure and quantum numbers except

a. In a given atom, the maximum number of electrons having principal quantum number n= 3, is 18

b. The number of orbitals in a given f subshell is 7

c. For n=4, the largest possible value of I is 3

d. For n=4, the largest possible value of mI is 2

(d)

 

Q. 35. Select the correct electron configuration for Cu (Z=29)

a. [Ar] 4s23d9

b. [Ar]4s13d10

c. [Ar]4s24p63d3

d. [Ar]4s14d9

(b)

 

Q. 36. Arrange potassium, rubidium, calcium and barium in order of increasing atomic size.

a. K < Ca < Rb < Ba

b. Ca < K < Rb < Ba

c. Ca < K < Ba < Rb

d. K < Ca < Ba < Rb

(b)

 

Q. 37. Element having smallest atomic radius among the following is

a. Li

b. Ne

c. Rb

d. Sr

(b)

 

Q. 38. The arrangement of sodium, oxygen, fluorine and strontium on the basis of increasing first

ionization energy is

a. Na < Sr < O < F

b. Sr < Na < O < F

c. Sr < Na < F < O

d. Na < Sr < F < O

(b)

 

Q. 39. Elements with _____ first ionization energies and _______ electron affinities generally form

cations.

a. low, very negative

b. high, positive or slightly negative

c. low, positive or slightly negative

d. high, very negative

(c)

 

Q. 40. In a Millikan oil-drop experiment, the charges on several different oil drops were as follows:

-5.92; -4.44; -2.96; -8.88. The units are arbitrary. What is the likely value of the electronic

charge in these arbitrary units?

a. -1.11

b. -1.48

c. -2.22

d. -2.96

(b)