Structure of Atom · Question 20

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.

1. 3.1, 6.2
2. 1.5, 3.0
3. 2.3, 4.6
4. 1.4, 2.8

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

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

1. 9.835 1012
2. 1.635 10-11
3. 1.635 10-18
4. 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 :

1. x1.35
2. 1.35x
3. x2
4. 2x

Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :

1. Both Statement I and Statement II are true
2. Statement I is true but Statement II is false
3. Statement I is false but Statement II is true
4. 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 :

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

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