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Structure of Atom · Question 5

JEE Main 2026 (Online) 5th April Morning ShiftMCQEasy📈 Topic in 13% papers+4−1
1

Arrange the following atomic orbitals of multi electron atoms in order of increasing energy. Choose the correct answer from the options given below:

  1. C < D < B < A < E
  2. B < A < E < C < D
  3. E < C < D < B < A
  4. E < B < A < D < C

Answer

(4) E < B < A < D < C

Solution

In a multi-electron atom the energy of an orbital is decided by the (n + l) rule: lower (n + l) ⇒ lower energy; for equal (n + l), lower n ⇒ lower energy. (m does not affect the energy.)

A. n = 3, l = 2 ⇒ 3d, n + l = 5

B. n = 4, l = 0 ⇒ 4s, n + l = 4

C. n = 6, l = 1 ⇒ 6p, n + l = 7

D. n = 5, l = 1 ⇒ 5p, n + l = 6

E. n = 2, l = 1 ⇒ 2p, n + l = 3

∴ Increasing energy: 2p < 4s < 3d < 5p < 6p, i.e. E < B < A < D < C

Answer: (4)

JEE Main 2026 (Online) 5th April Morning Shift

Keep practising — Structure of Atom

2

Identify the correct statements from the following : Choose the correct answer from the options given below:

  1. A, B and C Only
  2. A, B and D Only
  3. B, C and D Only
  4. A, C and D Only
JEE Main 2026 (Online) 5th April Morning Shift
3

Which of the following statement(s) is/are true ? Choose the correct answer from the options given below :

  1. A, B and C only
  2. A and C only
  3. C and D only
  4. A only
JEE Main 2026 (Online) 5th April Evening Shift
4

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?

  1. 5 : 1
  2. 5 : 0.81
  3. 5 : 1.75
  4. 5 : 27
JEE Main 2026 (Online) 4th April Morning Shift
5

Which of the following is correct set of 4 quantum numbers of 19th electron in Chromium (Atomic number = 24) in accordance with Aufbau principle?

  1. n = 3, l = 2, m = +2, s = + 12
  2. n = 3, l = 2, m = -2, s = + 12
  3. n = 4, l = 1, m = 0, s = + 12
  4. n = 4, l = 0, m = 0, s = + 12
JEE Main 2026 (Online) 4th April Morning Shift
6

The species having identical radii according to the Bohr's theory are : Choose the correct answer from the options given below :

  1. A and C Only
  2. A and E Only
  3. B and E Only
  4. C and D Only
JEE Main 2026 (Online) 4th April Evening Shift
7

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)

  1. 8.72 10-18
  2. 1.962 10-18
  3. 1.962 10-17
  4. 6.54 10-17
JEE Main 2026 (Online) 2nd April Morning Shift
8

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)

JEE Main 2026 (Online) 2nd April Evening Shift
9

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)

  1. 5R36, 3R16, 21R100
  2. 7R144, 3R16, 16R255
  3. 3R4, 3R16, 7R144
  4. 5R36, 8R9, 15R16
JEE Main 2026 (Online) 28th January Morning Shift
10

[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?

  1. D
  2. B
  3. C
  4. A
JEE Main 2026 (Online) 28th January Morning Shift
11

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 :

  1. A > C > B
  2. C > B > A
  3. B > A > C
  4. A > B > C
JEE Main 2026 (Online) 28th January Evening Shift

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