Structure of Atom · Question 7

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

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

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

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

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)

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

[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

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

Two positively charged particles m1 and m2 have been accelerated across the same potential difference of 200 kV as shown below. [figure] [Given mass of m1 = 1 amu and m2 = 4 amu] The de Broglie wavelength of m1 will be x times of m2. The value of x is (nearest integer)

The hydrogen spectrum consists of several spectral lines in Lyman series (L1, L2, L3 ; L1 has lowest energy among Lyman series). Similarly it consists of several spectral lines in Balmer series (B1, B2, B3 ; B1 has lowest energy among Balmer lines). The energy of L1 is x times the energy of B1. The value of x is 10-1. (Nearest integer)