Structure of Atom · Question 26

Correct statements for an element with atomic number 9 are: Choose the correct answer from the options given below:

1. A and B Only
2. A, C and D Only
3. A and C Only
4. 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:

1. B, C and D Only
2. A, C, D and E Only
3. A, B, D and E Only
4. A, D and E Only

The extra stability of half-filled subshell is due to : Identify the correct statements :

1. B, D and E only
2. A, B, D and E only
3. B, C and D only
4. A, B and D only

Which one of the following about an electron occupying the 1s orbital in a hydrogen atom is incorrect? (Bohr's radius is represented by a0)

1. The probability density of finding the electron is maximum at the nucleus
2. The total energy of the electron is maximum when it is at a distance a0 from the nucleus
3. The electron can be found at a distance 2a0 from the nucleus
4. The 1s orbital is spherically symmetrical

Consider the ground state of chromium atom (Z = 24). How many electrons are with Azimuthal quantum number l = 1 and l = 2 respectively ?

1. 16 and 5
2. 12 and 5
3. 12 and 4
4. 16 and 4

Which of the following postulate of Bohr's model of hydrogen atom is not in agreement with quantum mechanical model of an atom?

1. The electron in a H atom's stationary state moves in a circle around the nucleus.
2. An atom can take only certain distinct energies E1, E2, E3, etc. These allowed states of constant energy are called the stationary states of atom.
3. An atom in a stationary state does not emit electromagnetic radiation as long as it stays in the same state.
4. When an electron makes a transition from a higher energy stationary state to a lower energy stationary state, then it emits a photon of light.

For electrons in '2s' and '2p' orbitals, the orbital angular momentum values, respectively are:

1. 0 and 6 h2
2. 0 and 2 h2
3. 2 h2 and 0
4. h2 and 2 h2

According to Bohr's model of hydrogen atom, which of the following statement is incorrect?

1. Radius of 4th orbit is four times larger than that of 2nd orbit
2. Radius of 8th orbit is four times larger than that of 4th orbit
3. Radius of 6th orbit is three times larger than that of 4th orbit
4. Radius of 3rd orbit is nine times larger than that of 1st orbit

Which of the following statements are true? Choose the correct answer from the options given below:

1. (A) and (B) only
2. (B) and (D) only
3. (C) and (D) only
4. (A), (B) and (C) only