The question asks for the concept that describes light exhibiting both wave-like and particle-like properties. This phenomenon is a fundamental aspect of quantum mechanics and is known as wave-particle duality. We need to identify which of the given principles correctly describes this.
Correct Option: A) Complementarity principle — This principle, proposed by Niels Bohr, states that quantum objects like light exhibit complementary properties (wave and particle) that cannot be observed simultaneously in a single experiment. It directly explains the wave-particle duality.
This question asks about the relationship between the energy of a photon and its properties. This is a fundamental concept in quantum physics, specifically related to Planck's equation.
where:
where:
From this, we can express frequency in terms of wavelength: \(\nu = \frac{c}{\lambda}\).
This equation shows that the energy \(E\) is inversely proportional to the wavelength \(\lambda\).
B) Frequency — As derived from Planck's equation \(E = h\nu\), the energy \(E\) of a photon is directly proportional to its frequency \(\nu\), with \(h\) being Planck's constant.
The question asks for the main experimental evidence supporting the wave nature of matter. This concept is central to quantum mechanics, specifically de Broglie's hypothesis. We need to identify which phenomenon directly demonstrates particles behaving as waves.
Correct Option: B) Electron diffraction — This phenomenon directly demonstrates the wave nature of particles (electrons) by showing that they can diffract, a characteristic property of waves. The diffraction pattern observed for electrons scattering off a crystal lattice is analogous to X-ray diffraction, confirming de Broglie's hypothesis.
The question asks about the Heisenberg Uncertainty Principle, a fundamental concept in quantum mechanics. This principle states that certain pairs of physical properties of a particle, known as complementary variables, cannot both be known to arbitrary precision simultaneously. We need to identify which pair of properties from the given options fits this description.
C) Position and momentum is the correct answer. The Heisenberg Uncertainty Principle fundamentally states that it is impossible to precisely know both the position and the momentum of a particle simultaneously. The more accurately one is known, the less accurately the other can be known.
The question asks for the definition of the work function of a metal. The work function is a fundamental concept in the photoelectric effect, which describes the emission of electrons when light shines on a material.
B) Minimum energy required to emit photoelectrons. This accurately defines the work function of a metal. It is the threshold energy that an electron needs to absorb to escape the metal surface.
The question asks to identify the experiment that provided experimental confirmation for the wave nature of electrons. This requires knowledge of key experiments in quantum physics and their respective contributions.
A) Davisson-Germer experiment — This experiment directly demonstrated the wave nature of electrons by observing electron diffraction patterns from a nickel crystal, confirming de Broglie's hypothesis.