MODERN PHYSICS

What does Bohr's model of the atom explain?

• Atomic mass

• Atomic spectrum

• Radioactive decay

• Isotopes

Which spectral series of hydrogen lies in the visible region?

• Lyman

• Balmer

• Paschen

• Brackett

The quantum number l represents the:

• Principal energy level

• Spin of the electron

• Shape of the orbital

• Orientation of the orbital

The Stern-Gerlach experiment demonstrated the:

• Wave nature of electrons

• Discrete energy levels

• Quantization of angular momentum

• Existence of protons

The normal Zeeman effect involves splitting of spectral lines due to:

• Magnetic field

• Electric field

• Gravitational field

• None of the above

The selection rule for electronic transitions is:

• Δn=0

• Δl=±1

• Δm=0

• Δs=±1

The energy of an electron in the first orbit of a hydrogen atom is:

• −13.6 eV

• +13.6 eV

• 0 eV

• +3.4 eV

Rotational spectra of molecules are observed in the:

• Microwave region

• Infrared region

• Ultraviolet region

• X-ray region

The Raman effect is due to:

• Absorption of light

• Emission of light

• Scattering of light

• Reflection of light

Stokes lines in Raman spectra are:

• Higher in energy than the incident light

• Lower in energy than the incident light

• Equal in energy to the incident light

• Unrelated to the incident light