Quantum Mechanics Unit IV Quiz

A theory that describes the physical properties of nature at the scale of atoms and subatomic particles. It explains phenomena that cannot be understood by classical physics, like the quantization of energy, wave-particle duality, and the uncertainty principle.

The branch of physics that deals with the motion of macroscopic objects.

The inability of classical physics to explain the observed blackbody radiation spectrum, predicting an infinite energy density at high frequencies.

A German physicist who proposed that energy is not continuous but comes in discrete packets called 'quanta'. This idea was crucial in explaining the blackbody radiation spectrum.

The phenomenon where electrons are emitted from a metal surface when light shines on it. The energy of the ejected electrons depends on the frequency of the light, not its intensity.

A physicist who explained the photoelectric effect using the concept of light quanta (photons), further supporting the idea of quantization.

The model of the atom proposed by Ernest Rutherford, where a small, positively charged nucleus is surrounded by negatively charged electrons orbiting it.

The problem with the classical description of the atom where an accelerating electron should radiate energy and spiral into the nucleus, which doesn't actually happen.

The characteristic spectral lines emitted by specific elements, which are unique and can be used to identify different elements.

A Danish physicist who proposed a model of the hydrogen atom where electrons orbit the nucleus in specific, quantized energy levels. This explained the discrete spectral lines observed in hydrogen.

The idea proposed by Louis de Broglie that matter also exhibits wave-like properties, with a wavelength inversely proportional to its momentum.

A wave packet formed by superposition of waves with different frequencies. Its envelope travels at the group velocity, which is different from the phase velocity of individual waves.

The principle formulated by Werner Heisenberg which states that the product of uncertainties in position and momentum of a particle is always greater than or equal to Planck's constant divided by 4π.

The velocity at which a point of constant phase of a wave travels. It is given by the ratio of the angular frequency (ω) to the wave number (k).

The velocity at which the envelope of a wave packet travels. It is given by the derivative of the angular frequency (ω) with respect to the wave number (k).

The phenomenon where the phase velocity of a wave depends on its frequency, leading to different components of the wave traveling at different speeds and causing the wave packet to spread out.

A mathematical function that describes the state of a quantum mechanical system. It contains all the information about the system, including its position, momentum, and energy.

The first postulate of Quantum Mechanics states that every physically realizable state of a system is described by a wave function, called the state function, that contains all accessible physical information about the system in that state.

The second postulate of Quantum Mechanics states that the probability of finding a particle in a given infinitesimal volume (dV) at time (t) is given by the square of the absolute value of the wave function at that point and time.

The third postulate of Quantum Mechanics states that every observable in quantum mechanics is represented by an operator, which is used to obtain corresponding physical information from the state function.

The fourth postulate of Quantum Mechanics states that the time evolution of the state function of an isolated quantum system is governed by the time-dependent Schrödinger equation (TDSE).

The time-independent Schrödinger equation describes the energy states of a system where the Hamiltonian operator is independent of time and the energy is constant. It is essentially an eigenvalue equation for the Hamiltonian.

The time-dependent Schrödinger equation describes the evolution of a system where the Hamiltonian operator can depend on time. It describes how the wave function changes with time.

A simplified model in quantum mechanics where a particle is confined to a region of space with impenetrable walls. This model demonstrates the quantization of energy levels for a bound particle.

A quantum mechanical phenomenon where a particle has a non-zero probability of crossing a potential barrier even if its energy is less than the barrier height.

A type of microscope that uses quantum tunneling to image the surface of materials at atomic resolution. It relies on the phenomenon of electrons tunneling through a vacuum gap between a sharp tip and the sample.

Nuclear fusion is a process where two atomic nuclei combine to form a heavier nucleus, releasing energy. Quantum tunneling is an important factor in nuclear fusion, as it helps overcome the Coulomb barrier between the nuclei.

In VLSI electronics, quantum tunneling can lead to electron leakage, causing power loss and heating. This is a challenge for miniaturizing electronic devices as it limits the size of elements.

Quantum biology is the study of quantum phenomena in biological systems. Quantum tunneling is crucial in processes like electron transport in photosynthesis and redox reactions, as well as proton tunneling in DNA mutations.