Atomic Structure (F)

1. For which species Bohr's theory does not apply?

H

He+

Li2+

Be

2. Which one of the following is not isoelectronic pair?

Mg2+, Be2+

N3-, O2-

N3-, F-

F1-, Al3+

3. Which of the following configuration is not correct according to Hund's rule?

A

B

C

Option 4

4. From discharge tube experiments it is concluded that:

Mass of a proton is in fraction

Matter contained electron

Nucleus contains positive charge

Positive rays are heavier than proton

5. The energy of an electromagnetic radiation 3 m 10^-12 ergs. What is its wave length in nano meter

400

228.3

3000

662.5

6. Which one of the following statement is not correct?

Rydberg's constant and wave number have same unit

Lyman series of hydrogen spectrum occurs in the ultraviolet region.

The angular movement of the electron in the ground state of hydrogen atom is equal to h/2𝝅

The radius of first Bohr orbit of hydrogen atom is 2.116 ×108 cm.

7. The third line in Balmer sereis corresponds to an electronic transfer between which Bohr's orbit in hydrogen.

5 → 3

5 → 2

4 → 3

4 → 2

8. The electronic configuration of species M²⁺ is 1s², 2s², 2p⁶, 3s², 3p6,3d⁶ and its atomic weight is 56 amu, the number of neutron in the nucleus of species M is

20

26

28

30

9. When an electron of charge 'e' and mass 'm' moves with velocity 'v' about the nuclear charge Ze in a circular orbit of radius 'r', the P.E. of electron is given by

Ze2/r

-Ze2/r

Ze2/r2

Mv2/r

10. Which of the following does not tell about shells of an atom?

Principle quantum number , n

Azimuthal quantum number, l

Magnetic quantum number, m

Spin quantum number, s