Atomic Structure Test for IIT Jee| Aieee | 11th Class and 12th Class

Descriptive Questions(Section –I)

Total Marks: 26+20=46

This section contains 6 questions. All questions are compulsory and marks will be awarded on the basis of approach towards questions:

Question No.1.

Similar to electron diffraction, neutron diffraction microscope is also used for the determination of the structure of molecules. If the wavelength used here is 800 pm, calculate the characteristic velocity associated with the neutron. (3 Marks)

Question No. 2.

Neon gas is generally used in the sign boards. If it emits strongly at 616 nm, calculate (a) the frequency of emission, (b) distance travelled by this radiation in 30 s (c) energy of quantum and (d) number of quanta present if it produces 2 J of energy. (6 Marks)

Question No.3.

The number of electrons, protons and neutrons in a species are equal to 18, 16 and 16 respectively. Assign the proper symbol to the species. (3 marks)

Question No.4.

Describe Bohr’s model of atom and explain its usefulness over Rutherford model of atom. (5 Marks)

Question No.5.

State and explain the following: (6 Marks)

Ø Aufbau Principle

Ø De Broglie’s relation

Ø Pauli Exclusion Principle

Question No.6.

What will be the wavelength of a ball of mass 0.1 kg moving with a velocity of 10 m s^–1? (2 Marks)

Objective Type Questions (Section-II)

2 marks will be awarded to every right answer and 1 marks will be deducted for every wrong answer, No marks will be given on any unattempted question:

Q No.1

The energy of one mole of photons in (kilo joule/mole) of radiation whose frequency is 5*10^¹⁴ Hz is:

A) 199.51 B) 2008 C) 2099.51 D) 1990.51

Q No.2

For a p-electron, orbital angular moment is:

(A) √2h (B) h (C) √6h (D) 2h

Q.No.3

If the radius of 2nd Bohr orbit of hydrogen atom is r2. The radius of third Bohr orbit will be:

(A) 4/9r2 (B) 4r2 (C) 9/4r2 (D) 9r2

Q.NO.4

The velocity of electron in the ground state hydrogen atom is 2.18 x 106 ms–1. Its velocity in the second orbit would be:

(A) 1.09 x 106 ms–1 (B) 4.38 x 106 ms–1 (C) 5.5 x 105 ms–1 (D) 8.76 x 106 ms–1

Q.NO.5

Cathode rays were discovered by:

A) William Crookes B) Rutherford C)Chadwick D)None of these

Q.NO.6

Cathode rays are produced when the pressure in the discharge tube is:

A) 10000 mm of Hg B) 10^-2 mm of Hg C) 100 mm of Hg d) None of these

Q.No.7

Iselectronic species are:

A) Na⁺, F^- B) Al3+, O2- C) N,O D) A and B

Q.No.8

2P orbital have:

A) n=1,l=1 B) n=2,l=2 C) n=2,l=1 D) None of these

Q.No.9

Which of the following sets of quantum numbers are not possible?

(a) n = 0, l = 0, ml = 0, ms = + ½

(b) n = 1, l = 0, ml = 0, ms = – ½

(c) n = 1, l = 1, ml = 0, ms = + ½

(d) n = 2, l = 1, ml = 0, ms = – ½

A) a, b B)a, c C) a, d D)None of these

Q.No.10

The electronic configuration of Cu is:

A) [Ar] 4s¹, 3d¹⁰ B) [Ar] 4s², 3d⁹ C) [Ar] 3d¹⁰ ,4s² D)None of these