According to Bohr's theory, what is the angular momentum of an electron located in the fifth orbit? 

1. $25\frac{h}{\mathrm{\pi }}$

2. $1.0\frac{h}{\mathrm{\pi }}$

3. $10\frac{h}{\mathrm{\pi }}$

4. $2.5\frac{h}{\mathrm{\pi }}$

Consider the ground state of Cr atom (Z=24). The numbers of electrons with the azimuthal quantum numbers, l=1 and 2 are, respectively:

1. 12 and 4

2. 12 and 5

3. 16 and 4

4. 16 and 5

With a ground state energy of –13.6 eV for a hydrogen atom, what would be the energy in the second excited state?

1.  –6.8 eV 

2. –3.4 eV 

3. –1.51 eV 

4. –4.53 eV 

The wavelength (in nanometer) associated with a proton moving at 1.0 × 10³ ms^–1 (Mass of proton = 1.67 × 10^–27 kg and h = 6.63 × 10^–34 Js) is-:

1. 0.032 nm

2. 0.40 nm

3. 2.50 nm

4. 14.0 nm

Given that an electron in an atom moves at 600 m/s with an accuracy of 0.005%, what is the level of certainty in locating its position?
(h = 6.6 × 10^–34 kg m² s^–1, mass of electron,
e_m = 9.1 ×10^–31 kg) :

1. 1.52 × 10^–4 m
2. 5.10 × 10^–3 m
3. 1.92 × 10^–3 m
4. 3.84 × 10^–3 m

The energy required to break one mole of CI–Cl bonds in Cl₂ is 242 kJmol⁻¹. The wavelength of light capable of breaking a single Cl–Cl bond is:$\mathrm{}\mathrm{}\mathrm{}{\mathrm{}}^{\mathrm{}}{}^{\mathrm{}}{\mathrm{}}_{\mathrm{}}$

1. 494 nm

2. 594 nm

3. 640 nm

4. 700 nm

A gas absorbs a photon of 355 nm and emits at two wavelengths. If one of the emissions is at 680 nm, the other is at:

1. 1035 nm

2. 325 nm

3. 743 nm

4. 518 nm

The energy of an electron is given by E = – 2.178 × ${10}^{-18}\mathrm{J}\left(\frac{{\displaystyle {\mathrm{Z}}^2}}{{\displaystyle {\mathrm{n}}^2}}\right)$ Wavelength of light required to excite an electron in an hydrogen atom from level n = 1 to n = 2 will be:
(h = 6.62 × 10–³⁴ Js and c = 3.0 × 10⁸ ms^–1)

1. 6.500 × 10^–7 m

2. 8.500 × 10^–7 m

3. 1.214 × 10^–7 m

4. 2.816 × 10^–7 m

The correct set of four quantum numbers for the valence electrons of rubidium atom (Z = 37) is -

1. 5, 1, 0 + $\frac{1}{2}$

2. 5, 1, 1 + $\frac{1}{2}$

3. 5, 0, 1 +$\frac{1}{2}$

4. 5, 0, 0 + $\frac{1}{2}$

The electrons identified by quantum numbers n and l can be placed in order of increasing energy as:

a. n = 4, $\mathcal{l}$ = 1

b. n = 4, $\mathcal{l}$ = 0

c. n = 3, $\mathcal{l}$ = 2

d. n = 3, $\mathcal{l }$= 1