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Energy Heisenberg uncertainty principle

This can be understood as the spatial distance over which particles interact scales with the associated particle s wavelength and the fact that wavelength is inversely proportional to particle mass. Another way of expressing this is that more massive bodies experience a lesser uncertainty in their position at a given energy (Heisenberg uncertainty principle). This explains why ... [Pg.293]

Ultrafast time-resolved resonance Raman (TR ) spectroscopy experiments need to consider the relationship of the laser pulse bandwidth to its temporal pulse width since the bandwidth of the laser should not be broader than the bandwidth of the Raman bands of interest. The change in energy versus the change in time Heisenberg uncertainty principle relationship can be applied to ultrafast laser pulses and the relationship between the spectral and temporal widths of ultrafast transform-limited Gaussian laser pulse can be expressed as... [Pg.132]

Heisenberg uncertainty principle the location and the energy of a small particle such an an electron cannot both be known precisely at any given time. [Pg.354]

In this equation, H, the Hamiltonian operator, is defined by H = — (h2/8mir2)V2 + V, where h is Planck s constant (6.6 10 34 Joules), m is the particle s mass, V2 is the sum of the partial second derivative with x,y, and z, and V is the potential energy of the system. As such, the Hamiltonian operator is the sum of the kinetic energy operator and the potential energy operator. (Recall that an operator is a mathematical expression which manipulates the function that follows it in a certain way. For example, the operator d/dx placed before a function differentiates that function with respect to x.) E represents the total energy of the system and is a number, not an operator. It contains all the information within the limits of the Heisenberg uncertainty principle, which states that the exact position and velocity of a microscopic particle cannot be determined simultaneously. Therefore, the information provided by Tint) is in terms of probability I/2 () is the probability of finding the particle between x and x + dx, at time t. [Pg.3]

One of the first uses of ESR spectra to measure the rate of a chemical reaction was by Ward and Weissman in the early 1950s.1 They made use of a form of the Heisenberg uncertainty principle (eqn 5.1) to relate the lifetime of a spin state to the uncertainty in the energy of the state. [Pg.92]

The Heisenberg uncertainty principle dictates that energy and time associated with an atomic-scale system cannot be determined jointly within arbitrary precision ... [Pg.54]

The Bohr model is a determinant model of an atom. It implies that the position of the electron is exactly known at any time in the future, once that position is known at the present. The distance of the electron from the nucleus also is exactly known, as is its energy. And finally, the velocity of the electron in its orbit is exactly known. All of these exactly known quantities—position, distance from nucleus, energy, and velocity—can t, according to the Heisenberg uncertainty principle, be known with great precision simultaneously. [Pg.173]

The Heisenberg Uncertainty Principle, describing a dispersion in location and momentum of material particles that depends inversely on their mass, gives rise to vibrational zero-point energy differences between molecules that differ only isotopically. These zero-point energy differences are the main origin of equilibrium chemical isotope effects, i.e., non-unit isotopic ratios of equilibrium constants such as K /Kj) for a reaction of molecules bearing a protium (H) atom or a deuterium (D) atom. [Pg.29]

The residual energy (designated of a harmonic oscillator in the ground state. The Heisenberg Uncertainty Principle does not permit any state of completely defined position and momentum. A one-dimensional harmonic oscillator has energy levels corresponding to ... [Pg.714]

What is the lowest possible energy for the harmonic oscillator defined in Eq. (5.10) Using classical mechanics, the answer is quite simple it is the equilibrium state with x 0, zero kinetic energy and potential energy E0. The quantum mechanical answer cannot be quite so simple because of the Heisenberg uncertainty principle, which says (roughly) that the position and momentum of a particle cannot both be known with arbitrary precision. Because the classical minimum energy state specifies both the momentum and position of the oscillator exactly (as zero), it is not a valid quantum... [Pg.122]

The zero point energy of a particle in a one dimensional box at a infinite height is The occurrence of zero point energy in accordance with the Heisenberg uncertainty principle is ... [Pg.161]

We cannot extrapolate our knowledge of everyday macroscopic world to the world of subatomic dimensions. The Heisenberg uncertainty principle, the wave character of particle motion and quantization of energy become important when the masses of the particles become comparable to Planck s constant h. [Pg.46]

Linewidth is governed by the Heisenberg uncertainty principle, which says that the shorter the lifetime of the excited state, the more uncertain is its energy ... [Pg.462]

Heisenberg uncertainty principle Certain pairs of physical quantities cannot be known simultaneously with arbitrary accuracy. If 8E is the uncertainty in the energy difference between two atomic states and 8f is the... [Pg.693]

By analogy, the energy uncertainty associated with a given state, AE, through the Heisenberg uncertainty principle can be obtained from the lifetime contributed by each decay mode. If we use the definition AE = T, the level width, then we can express F in terms of the partial widths for each decay mode T, such that... [Pg.76]

It is interesting to note that the vibrational model of the nucleus predicts that each nucleus will be continuously undergoing zero-point motion in all of its modes. This zero-point motion of a quantum mechanical harmonic oscillator is a formal consequence of the Heisenberg uncertainty principle and can also be seen in the fact that the lowest energy state, N = 0, has the finite energy of h to/2. [Pg.159]

The measured half-life of the state is 89.4 ps, which corresponds to a energy width, T, or AE, due to the Heisenberg uncertainty principle of ... [Pg.242]

Many of the processes which determine line widths can be removed by appropriately designed experiments, but it is almost impossible to avoid so-called natural line broadening. This arises from the spontaneous emission process (governed by the Einstein A coefficient) described in the previous section. Spontaneous emission terminates the lifetime of the upper state involved in a transition, and the Heisenberg uncertainty principle states that the lifetime of the state (At) and uncertainty in its energy (A E) are related by the expression... [Pg.273]

Electrons that are bound to nuclei are found in orbitals. Orbitals are mathematical descriptions that chemists use to explain and predict the properties of atoms and molecules. The Heisenberg uncertainty principle states that we can never determine exactly where the electron is nevertheless, we can determine the electron density, the probability of finding the electron in a particular part of the orbital. An orbital, then, is an allowed energy state for an electron, with an associated probability function that defines the distribution of electron density in space. [Pg.1310]

The wave mechanical treatment of the hydrogen atom does not provide more accurate values than the Bohr model did for the energy states of the hydrogen atom. It does, however, provide the basis for describing the probability of finding electrons in certain regions, which is more compatible with the Heisenberg uncertainty principle. Note that the solution of this three-dimensional wave equation resulted in the introduction of three quantum numbers (n, /, and mi). A principle of quantum mechanics predicts that there will be one quantum number for... [Pg.22]


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