Atomic Structure MCQs

1. All of the following were theorized by Bohr in his description of the atom except

A. The angular momentum of electrons in multiples of h/2?

B. Electrons revolve in discrete circular orbits

C. The energy of each electron is directly proportional to n2

D. Electrons radiate energy continuously in a given orbit

✅ The correct answer is option D.

2. The letters sp d and f are used to represent which quantum numbers

A. Principal

B. Azimuthal

C. Magnetic

D. Spin

✅ The correct answer is option B.

3. The magnetic quantum number (QN) has its values determined directly by the value of

A. Principal (QN)

B. Azimuthal (QN)

C. Spin (QN)

D. Both a & b

✅ The correct answer is option B.

4. The atomic number of an element having the maximum number of unpaired electrons in p-subshell is

A. 7

B. 10

C. 12

D. 16

✅ The correct answer is option A.

5. The maximum number of electron in a subshell with? = 3fs

A. 6

B. 10

C. 14

D. 18

✅ The correct answer is option C.

6. The radius of the third shell of H-atom is

A. 5.761 A?

B. 4.761 A?

C. 6.671 A?

D. 3.716 A?

✅ The correct answer is option B.

7. When an atom absorbs energy the lines in the spectrum will appear which are

A. Brighter

B. Darker

C. Colourless

D. Hard to locate

✅ The correct answer is option B.

8. Colour of fluorescence produced by cathode rays depends upon

A. Temperature

B. Pressure

C. Volume

D. Composition of glass

✅ The correct answer is option D.

9. Which one is not true about cathode rays?

A. 9.11×10-31 Kg

B. Cast shadow

C. Heat up the platinum foil

D. Cannot ionize

✅ The correct answer is option D.

10. Positive rays are produced

A. By burning of gas

B. By cooling of the gas

C. By the bombardment of cathode rays on gas molecules

D. From anode like cathode rays produced from a cathode

✅ The correct answer is option C.