Consider two radiations of wavelengths 1. 1 = 2000 Å 2. 2 = 6000 Å The ratio of the energies of these two radiations ( E1E2 ) is (Nearest integer).
Structure of Atom
Previous year questions with solutions · 2025 – 2026
Year-wise statistics questions · papers · average per paper · weightage
| Year | Questions | Papers | Avg / paper | Weightage |
|---|---|---|---|---|
| 2026 | 26 | 19 | 1.4 | 5.47% ↑26.3% |
| 2025 | 13 | 12 | 1.1 | 4.33% |
If shortest wavelength of hydrogen atom in Lyman series is x, then longest wavelength in Balmer series of He+ is:
- 9x5
- 36x5
- x4
- 5x9
Match the LIST-I with LIST-II
- A-IV, B-I, C-III, D-II
- A-IV, B-II, C-III, D-I
- A-III, B-I, C-IV, D-II
- A-IV, B-III, C-II, D-I
The Bohr radius of a hydrogen like species is 70.53 pm. The species and the stationary state (n) are respectively (Given : Hydrogen atom Bohr radius is 52.9 pm)
- Li2+, 3
- He+, 3
- He+, 2
- Li2+, 2
Arrange the following atomic orbitals of multi electron atoms in order of increasing energy. Choose the correct answer from the options given below:
- C < D < B < A < E
- B < A < E < C < D
- E < C < D < B < A
- E < B < A < D < C
Identify the correct statements from the following : Choose the correct answer from the options given below:
- A, B and C Only
- A, B and D Only
- B, C and D Only
- A, C and D Only
Which of the following statement(s) is/are true ? Choose the correct answer from the options given below :
- A, B and C only
- A and C only
- C and D only
- A only
What is the ratio of wave number of first line (lowest energy line) of Balmer series of H atomic spectrum to first line of its Brackett series?
- 5 : 1
- 5 : 0.81
- 5 : 1.75
- 5 : 27
Which of the following is correct set of 4 quantum numbers of 19th electron in Chromium (Atomic number = 24) in accordance with Aufbau principle?
- n = 3, l = 2, m = +2, s = + 12
- n = 3, l = 2, m = -2, s = + 12
- n = 4, l = 1, m = 0, s = + 12
- n = 4, l = 0, m = 0, s = + 12
The species having identical radii according to the Bohr's theory are : Choose the correct answer from the options given below :
- A and C Only
- A and E Only
- B and E Only
- C and D Only
What is the energy (in J atom-1) required for the following process ? Li2+(g) Li3+(g) + e- (Take the ionization energy for the H atom in the ground state as 2.18 10-18 J atom-1)
- 8.72 10-18
- 1.962 10-18
- 1.962 10-17
- 6.54 10-17
The surface of sodium metal is irradiated with radiation of wavelength x nm. The kinetic energy of ejected electrons is 2.8 10-20 J. The work function of sodium is 2.3 eV. The value of x is 102 nm. (Nearest integer) (Given : h = 6.6 10-34 J s; 1 eV = 1.6 10-19 J; c = 3.0 108 m s-1)
The wave numbers of three spectral lines of H atom are considered. Identify the set of spectral lines belonging to Balmer series. (R = Rydberg constant)
- 5R36, 3R16, 21R100
- 7R144, 3R16, 16R255
- 3R4, 3R16, 7R144
- 5R36, 8R9, 15R16
[figure] Figure 1. electron probability density for 2s orbital [figure] Figure 2. wave function for 2s orbital Which of the following point in Figure 2 most accurately represents the nodal surface as shown in Figure 1?
- D
- B
- C
- A
The wavelength of photon 'A' is 400 nm. The frequency of photon 'B' is 1016 s-1. The wave number of photon 'C' is 104 cm-1. The correct order of energy of these photons is :
- A > C > B
- C > B > A
- B > A > C
- A > B > C
Two positively charged particles m1 and m2 have been accelerated across the same potential difference of 200 kV as shown below. [figure] [Given mass of m1 = 1 amu and m2 = 4 amu] The de Broglie wavelength of m1 will be x times of m2. The value of x is (nearest integer)
The hydrogen spectrum consists of several spectral lines in Lyman series (L1, L2, L3 ; L1 has lowest energy among Lyman series). Similarly it consists of several spectral lines in Balmer series (B1, B2, B3 ; B1 has lowest energy among Balmer lines). The energy of L1 is x times the energy of B1. The value of x is 10-1. (Nearest integer)
The wavelength of spectral line obtained in the spectrum of Li2+ ion, when the transition takes place between two levels whose sum is 4 and difference is 2, is
- 1.14 10-6 cm
- 2.28 10-6 cm
- 1.14 10-7 cm
- 2.28 10-7 cm
Given, (A) n = 5, ml = -1 (B) n = 3, l = 2, ml = -1, ms = + 12 The maximum number of electron(s) in an atom that can have the quantum numbers as given in (A) and (B) respectively are :
- 4 and 1
- 2 and 4
- 26 and 1
- 8 and 1
Which of the following statements regarding the energy of the stationary state is true in the following one-electron systems ?
- +2.18 10-18 J for second orbit of He+ ion
- +8.72 10-18 J for first orbit of He+ ion
- -1.09 10-18 J for second orbit of H atom.
- -2.18 10-18 J for third orbit of Li2+ ion
The work functions of two metals (MA and MB) are in the 1 : 2 ratio. When these metals are exposed to photons of energy 6 eV, the kinetic energy of liberated electrons of MA : MB is in the ratio of 2.642 : 1. The work functions (in eV) of MA and MB are respectively.
- 3.1, 6.2
- 1.5, 3.0
- 2.3, 4.6
- 1.4, 2.8
Identify the INCORRECT statements from the following : Choose the correct answer from the options given below :
- A and D Only
- A and C Only
- A and B Only
- B and C Only
The energy required by electrons, present in the first Bohr orbit of hydrogen atom to be excited to second Bohr orbit is J mol-1. Given: RH = 2.18 10-11 ergs.
- 9.835 1012
- 1.635 10-11
- 1.635 10-18
- 9.835 105
The energy of first (lowest) Balmer line of H atom is x J. The energy (in J) of second Balmer line of H atom is :
- x1.35
- 1.35x
- x2
- 2x
Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :
- Both Statement I and Statement II are true
- Statement I is true but Statement II is false
- Statement I is false but Statement II is true
- Both Statement I and Statement II are false
Consider the following spectral lines for atomic hydrogen : The correct arrangement of the above lines in ascending order of energy is :
- D < C < A < B
- A < B < C < D
- D < A < C < B
- C < D < B < A
Correct statements for an element with atomic number 9 are: Choose the correct answer from the options given below:
- A and B Only
- A, C and D Only
- A and C Only
- C and D Only
The energy of an electron in the first Bohr orbit of the H-atom is -13.6 eV. The magnitude of energy value of an electron in the first excited state of Be3+ is eV (nearest integer value).
[figure] Which of the following statements are correct, if the threshold frequency of caesium is 5.16 1014 Hz? Choose the correct answer from the options given below:
- B, C and D Only
- A, C, D and E Only
- A, B, D and E Only
- A, D and E Only
The extra stability of half-filled subshell is due to : Identify the correct statements :
- B, D and E only
- A, B, D and E only
- B, C and D only
- A, B and D only