Energy quantization in atoms

You will already know from your studies that the energy levels of atoms and molecules are quantized, i.e. there are discrete energy levels in atoms and molecules (Figure 1.1). 

We now have evidence that electron energy levels in atoms are quantized. 

What if energy levels in atoms were not quantized What are some differences we would notice ... 

O 78. The "Chemistry in Focus" segment Fireworks discusses some of the chemicals that give rise to the colors of fireworks. How do these colors support the existence of quantized energy levels in atoms ... 

Unlike the processes of absorption and luminescence emission, scattering of light need not involve an electronic transition between quantized energy levels in atoms or molecules. Instead, a randomization in the... 

Based largely upon spectroscopic measurements (i.e., the observation of quantized absorption and emission of energy—as in atomic spectroscopy, about which you may have already heard, and other forms of spectroscopy to be discussed in Chapter 2) and the utility of the concept in making successful predictions, we define as an orbital that particular volume in space, near a nucleus, in which there is a high probability of finding an electron associated with that nucleus. By the Pauli exclusion principle, no more than two electrons can occupy a given orbital and if there are two electrons in the orbital, they must differ with regard to a property called spin. This property has only two possible values, frequently symbolized by the notations t and i (or sometimes by +V2 and -Vi, respectively), and if two electrons have the same values (i.e., tt or x(i) for this property, they are said to be unpaired and they cannot occupy the same orbital. Only paired (Ti) electrons can occupy the same orbital. 

We now have evidence that electron energy levels in the atoms are quantized. Some of this evidence is discussed in this chapter. What if energy levels in atoms were not quantized What are some differences we would notice ... 

Because these photons are produced when an electron moves from one energy level to another, the electronic energy levels in an atom must be quantized, that is, limited to particular values. Moreover, it would seem that by measuring the spectrum of an element it should be possible to unravel its electronic energy levels. This is indeed possible, but it isn t easy. Gaseous atoms typically give off hundreds, even thousands, of spectral lines. 

Nieb Bohr (1885-1962) was a Danish physicist whose discovery of the quantization of atomic energy levels won him a Nobel Prize in 1922. Bohr headed a world-renowned institute for atomic studies in Copenhagen in the 1920s and 1930s. 

The Schrodinger equation has solutions only for specific energy values, hi other words, the energy of an atom is quantized, restricted to certain values. For each quantized energy value, the Schrodinger equation generates a wave function that describes how the electrons are distributed in space. 

Note that these vibrational states in the solid are not recognizable in terms of those of the gaseous or liquid states. And, the rotational states appear to be completely absent. It has been determined that solids have quite different vibrational states which are called "phonon modes". These vibrational states are quantized vibrational modes within the solid structure wherein the atoms all vibrate together in a specific pattern. That is, the vibrations have clearly defined energy modes in the solid. 

The first application of quantum theory to a problem in chemistry was to account for the emission spectrum of hydrogen and at the same time explain the stability of the nuclear atom, which seemed to require accelerated electrons in orbital motion. This planetary model is rendered unstable by continuous radiation of energy. The Bohr postulate that electronic angular momentum should be quantized in order to stabilize unique orbits solved both problems in principle. The Bohr condition requires that... 

The energy of an atom is quantized, existing in only certain distinct energy states. 

The theory of color and light production, however, involves the energy levels available for electrons in atoms and molecules, according to the beliefs of modern chemical theory. In an atom or molecule, there are a number of "orbitals" or energy levels that an electron may occupy. Each of these levels corresponds to a discrete energy value, and only these energies are possible. The energy is said to be quantized, or restricted to certain values that depend on the nature of the particular atom or molecule. 

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