Physics Quiz For B.Sc.

Molecule has all types of energy

Bohr proposed the concept of elliptical orbits in his model of the atom. He suggested that electrons revolve around the nucleus in specific energy levels, and these orbits are elliptical in shape. This model was a significant advancement in understanding the behavior of electrons and their distribution within an atom. Rutherford, Sommerfeld, and Einstein made other important contributions to atomic theory but did not specifically propose the concept of elliptical orbits.

(d) Angular momentum L = mvr = nh/2π

Visible light's wavelength range is typically measured in micrometers (µm), which is the correct answer given. The range of 0.39 - 0.77 µm corresponds to the wavelengths of light that are visible to the human eye, with shorter wavelengths appearing as violet and longer wavelengths appearing as red.

When the energy required to ionize the hydrogen atom is given as 13.6 eV, it means that this is the energy required to completely remove an electron from the atom when it is in the ground state (n = 1). In order to remove an electron from the n = 2 energy level, the energy required would be less than the ionization energy. Since the energy levels of hydrogen are quantized, the energy required to remove an electron from n = 2 would be lower than the ionization energy, but not zero. Therefore, the correct answer is 3.4 eV, which is less than 13.6 eV but greater than zero.

The transition zone for Raman spectra refers to the region between vibrational and rotational levels. Raman spectroscopy involves the interaction of light with molecular vibrations, causing a shift in energy levels. Vibrational levels correspond to the different vibrational states of a molecule, while rotational levels correspond to the different rotational states. The transition zone is where the energy changes from predominantly vibrational to predominantly rotational, and this is where Raman scattering occurs.

Luminescence occurs when excited electrons return to their ground state, releasing photons in the process. This phenomenon is known as fluorescence or phosphorescence, depending on the duration of the emitted light. When electrons are excited to higher energy levels, they eventually drop back down to their original energy level, emitting photons in the process. This is the most common explanation for luminescence and is the correct answer in this case.

(b) e2/r , since K.E = ke2/2r

The correct order of different types of energies is Eel (electrical energy), Evib (vibrational energy), Erot (rotational energy), and Etr (translational energy). This order is based on the hierarchy of energy types, where electrical energy is the highest in the hierarchy, followed by vibrational, rotational, and translational energy.

The charge of a proton is 1737 times that of an electron. This is because the proton carries a positive charge, while the electron carries a negative charge. The ratio of their charges is determined by the fundamental properties of these particles.