381.

Which one of the following transitions of an electron in hydrogen atom emits radiation of the lowest wavelength?

• n₂ = ∞ to n₁=2

• n₂= 4 to n₁ =3

• n₂= 2 to n₁ =1

• n₂ = 5 to n₁=3

Which one of the following conditions is incorrect for a well behaved wave function (Ψ)?

• Ψ must be fine

• Ψ must be single valued

• Ψ must be infinite

• Ψ must be continuous

The electron affinity values of elements A, B, C and D are respectively -135, -60, -200 and -348 kJ mol^-1. The outer electronic configuration of element B is

• 3s² 3p⁵

• 3s² 3p⁴

• 3s² 3p³

• 3s² 3p²

Which one of the following frequencies of radiation (in Hz) has a wavelength of 600 nm?

• 2.0 × 10¹³ 

• 5.0 × 10¹⁶ 

• 2.0 × 10¹⁴ 

• 5.0 × 10¹⁴ 

According to Bohr's theory which one of the following values of angular momentum of hydrogen atom is not permitted?

• $\frac{1.25 \mathrm{h}}{\mathrm{\pi }}$

• $\frac{\mathrm{h}}{\mathrm{\pi }}$

• $\frac{1.5 \mathrm{h}}{\mathrm{\pi }}$

• $\frac{0.5 \mathrm{h}}{\mathrm{\pi }}$

The number of radial nodes of 3s and 2p orbitals respectively are

• 0, 2

• 2, 0

• 1, 2

• 2, 1

The basis of quantum mechanical model of an atom is

• angular momentum of electron

• quantum numbers

• dual nature of electron

• black body radiation

The quantum number which explains the line spectra observed as doublets in case of hydrogen and alkali metals and doublets and triplets in case of alkaline earth metals is

• spin

• azimuthal

• magnetic

• principal

A compound absorbs light in the wavelength region 490-500 nm. Its complementary colour is

• red

• blue

• orange

• blue-green

Which of the following sets of quantum numbers is correct for an electron in 3d-orbital?

• n = 3; l = 2; m = -3; s = +$\frac{1}{2}$

• n = 3; l = 3; m = +3; s = -$\frac{1}{2}$

• n = 3; l = 2; m = -2; s = +$\frac{1}{2}$

• n = 3; l = 2; m = -3; s = -$\frac{1}{2}$