91.

Identify the nuclear reaction that differs from the rest.

• γ- decay

• κ- capture

• Positron emission

• β-decay

The radius of the first Bohr orbit of hydrogen atom is 0.529 Å. The radius of the third orbit of H⁺ will be

• 8.46 Å

• 0.705 Å

• 1.59 Å

• 4.29 Å

Which diagram best represents the appearance of the line spectrum of atomic hydrogen in the visible region?

The correct set of quantum numbers (n, l and m respectively) for the unpaired electron of chlorine atom is :

• 2, 1, 0

• 2, 1, 1

• 3, 1, 1

• 3, 2, 1

The relationship between the energy E₁ of the radiation with a wavelength 8000 Å and the energy E₂ of the radiation with a wavelength Å 16000  is:

• E₁ = 6E₂

• E₁ = 2E₂

• E₁ = 4E₂

• E₁ = 4E₂

Calculate the mass loss in the following.

${}_1{}^2\mathrm{H} + {}_1{}^3\mathrm{H} \to {}_2{}^4\mathrm{H} + {}_0{}^1\mathrm{n}$

[Given the masses : ²H = 2.014;³H = 3.016; He = 4.004; n = 1.008 amu]  

• 0.018 amu

• 0.18 amu

• 0.0018 amu

• 1.8 amu

The observation that the ground state of nitrogen atom has 3 unpaired electrons in its electronic configuration and not otherwise is associated with:

• Pauli's exclusion principle

• Hund's rule of maximum multiplicity

• Heisenberg's uncertainty relation

• Ritz combination principle

The first artificial disintegration of an atomic nucleus was achieved by

• Geiger

• Wilson

• Madam Curie

• Rutherford

When any radioactive element emits β particle, some product is obtained. They both are

• isotopes

• isobars

• isomers

• isotoes

Electrical field is used to deflect

• α and β particles

• α and γ particles

• α,  β and γ particles

• β and γ particles