Q53 / 180 · COMEDK 2026 (9 May Shift 2) · Chemistry
Which of the following statement is correct?
- AAzimuthal Quantum number explains about spatial orientation of orbital
- BHeisenberg uncertainty principle can be applied to all the objects and for macroscopic objects the uncertainty is extremely large
- CPhoton has momentum as well as wavelength, but electrons do not have momentum and wavelength
- Correct answerDIn photoelectric effect if frequency $\nu > \nu_o$, then photoelectrons are ejected with certain kinetic energy
Solution
The azimuthal quantum number ($l$) describes the shape of the orbital, whereas the magnetic quantum number ($m_l$) describes the spatial orientation of the orbital. Thus, the first statement is incorrect.
The Heisenberg uncertainty principle applies to all objects, but for macroscopic objects, the mass is large, making the uncertainty in position and velocity extremely small and negligible. Thus, the second statement is incorrect.
According to the de Broglie hypothesis, all material particles in motion, including electrons, possess both momentum and wavelength ($\lambda = \dfrac{h}{p}$). Thus, the third statement is incorrect.
In the photoelectric effect, if the frequency of incident light $\nu$ is greater than the threshold frequency $\nu_o$, the photoelectrons are ejected with a certain kinetic energy given by Einstein's photoelectric equation: $K.E. = h(\nu - \nu_o)$. Thus, the fourth statement is correct.
Answer: In photoelectric effect if frequency $\nu > \nu_o$, then photoelectrons are ejected with certain kinetic energy
The Heisenberg uncertainty principle applies to all objects, but for macroscopic objects, the mass is large, making the uncertainty in position and velocity extremely small and negligible. Thus, the second statement is incorrect.
According to the de Broglie hypothesis, all material particles in motion, including electrons, possess both momentum and wavelength ($\lambda = \dfrac{h}{p}$). Thus, the third statement is incorrect.
In the photoelectric effect, if the frequency of incident light $\nu$ is greater than the threshold frequency $\nu_o$, the photoelectrons are ejected with a certain kinetic energy given by Einstein's photoelectric equation: $K.E. = h(\nu - \nu_o)$. Thus, the fourth statement is correct.
Answer: In photoelectric effect if frequency $\nu > \nu_o$, then photoelectrons are ejected with certain kinetic energy
Hence, the correct answer is option: 'D'.