6 3 development of quantum theory u2013 chemistry

Why did the model work so well describing hydrogen and one-electron ions, but could not correctly predict the emission spectrum for helium or any larger atoms? To answer these questions, scientists needed to completely revise the way they thought about matter. We know how matter behaves in the macroscopic world—objects that are large enough to be seen by the naked eye follow the rules of classical physics. A billiard ball moving on a table will behave like a particle: It will continue in a straight line unless it collides with another ball or the table cushion, or is acted on by some other force such as friction.

6.3 Development of Quantum Theory

In other words, the ball is moving in a classical trajectory. This is the typical behavior of a classical object.

6 3 development of quantum theory u2013 chemistry

Figure 1. An interference pattern on the water surface is formed by interacting waves. The waves are caused by reflection of water from the rocks.

When waves interact with each other, they show interference patterns that are not displayed by macroscopic particles such as the billiard ball. For example, interacting waves on the surface of water can produce interference patters similar to those shown on Figure 1. This is a case of wave behavior on the macroscopic scale, and it is clear that particles and waves are very different phenomena in the macroscopic realm.

As technological improvements allowed scientists to probe the microscopic world in greater detail, it became increasingly clear by the s that very small pieces of matter follow a different set of rules from those we observe for large objects.

The unquestionable separation of waves and particles was no longer the case for the microscopic world. One of the first people to pay attention to the special behavior of the microscopic world was Louis de Broglie. He asked the question: If electromagnetic radiation can have particle-like character, can electrons and other submicroscopic particles exhibit wavelike character? In his doctoral dissertation, de Broglie extended the wave—particle duality of light that Einstein used to resolve the photoelectric-effect paradox to material particles.

This is called the de Broglie wavelength. Although these two symbols are identical, they mean very different things. Figure 2. If an electron is viewed as a wave circling around the nucleus, an integer number of wavelengths must fit into the orbit for this standing wave behavior to be possible.

6 3 development of quantum theory u2013 chemistry

Since the de Broglie expression relates the wavelength to the momentum and, hence, velocity, this implies:.Why did the model work so well describing hydrogen and one-electron ions, but could not correctly predict the emission spectrum for helium or any larger atoms? To answer these questions, scientists needed to completely revise the way they thought about matter.

6 3 development of quantum theory u2013 chemistry

We know how matter behaves in the macroscopic world—objects that are large enough to be seen by the naked eye follow the rules of classical physics. A billiard ball moving on a table will behave like a particle: It will continue in a straight line unless it collides with another ball or the table cushion, or is acted on by some other force such as friction.

In other words, the ball is moving in a classical trajectory. This is the typical behavior of a classical object. When waves interact with each other, they show interference patterns that are not displayed by macroscopic particles such as the billiard ball. For example, interacting waves on the surface of water can produce interference patters similar to those shown on Figure 1. This is a case of wave behavior on the macroscopic scale, and it is clear that particles and waves are very different phenomena in the macroscopic realm.

Figure 1. An interference pattern on the water surface is formed by interacting waves. The waves are caused by reflection of water from the rocks. As technological improvements allowed scientists to probe the microscopic world in greater detail, it became increasingly clear by the s that very small pieces of matter follow a different set of rules from those we observe for large objects. The unquestionable separation of waves and particles was no longer the case for the microscopic world.

One of the first people to pay attention to the special behavior of the microscopic world was Louis de Broglie. He asked the question: If electromagnetic radiation can have particle-like character, can electrons and other submicroscopic particles exhibit wavelike character? In his doctoral dissertation, de Broglie extended the wave—particle duality of light that Einstein used to resolve the photoelectric-effect paradox to material particles.

This is called the de Broglie wavelength. Although these two symbols are identical, they mean very different things. Figure 2. If an electron is viewed as a wave circling around the nucleus, an integer number of wavelengths must fit into the orbit for this standing wave behavior to be possible.

Since the de Broglie expression relates the wavelength to the momentum and, hence, velocity, this implies:. Classical angular momentum L for a circular motion is equal to the product of the radius of the circle and the momentum of the moving particle p. Figure 3. The diagram shows angular momentum for a circular motion.The light produced by a red neon sign is due to the emission of light by excited neon atoms. Qualitatively describe the spectrum produced by passing light from a neon lamp through a prism.

An FM radio station found at What is the wavelength of these radio waves in meters? FM, an FM radio station, broadcasts at a frequency of 9. A bright violet line occurs at What amount of energy, in joules, must be released by an electron in a mercury atom to produce a photon of this light? Light with a wavelength of What is the energy, in joules, per photon of this orange light?

Heated lithium atoms emit photons of light with an energy of 2. Calculate the frequency and wavelength of one of these photons. What is the total energy in 1 mole of these photons? What is the color of the emitted light? A photon of light produced by a surgical laser has an energy of 3. Calculate the frequency and wavelength of the photon. What is the total energy in 1 mole of photons?

When rubidium ions are heated to a high temperature, two lines are observed in its line spectrum at wavelengths a 7. What are the frequencies of the two lines? What color do we see when we heat a rubidium compound? The emission spectrum of cesium contains two lines whose frequencies are a 3. What are the wavelengths and energies per photon of the two lines?

What color are the lines? Photons of infrared radiation are responsible for much of the warmth we feel when holding our hands before a fire. These photons will also warm other objects. How many infrared photons with a wavelength of 1. One of the radiographic devices used in a dentist's office emits an X-ray of wavelength 2.

What is the energy, in joules, and frequency of this X-ray? The eyes of certain reptiles pass a single visual signal to the brain when the visual receptors are struck by photons of a wavelength of nm.

If a total energy of 3. RGB color television and computer displays use cathode ray tubes that produce colors by mixing red, green, and blue light. If we look at the screen with a magnifying glass, we can see individual dots turn on and off as the colors change.Why did the model work so well describing hydrogen and one-electron ions, but could not correctly predict the emission spectrum for helium or any larger atoms?

To answer these questions, scientists needed to completely revise the way they thought about matter. We know how matter behaves in the macroscopic world—objects that are large enough to be seen by the naked eye follow the rules of classical physics. A billiard ball moving on a table will behave like a particle: It will continue in a straight line unless it collides with another ball or the table cushion, or is acted on by some other force such as friction.

In other words, the ball is moving in a classical trajectory. This is the typical behavior of a classical object.

When waves interact with each other, they show interference patterns that are not displayed by macroscopic particles such as the billiard ball.

For example, interacting waves on the surface of water can produce interference patters similar to those shown on Figure 6. This is a case of wave behavior on the macroscopic scale, and it is clear that particles and waves are very different phenomena in the macroscopic realm. As technological improvements allowed scientists to probe the microscopic world in greater detail, it became increasingly clear by the s that very small pieces of matter follow a different set of rules from those we observe for large objects.

The unquestionable separation of waves and particles was no longer the case for the microscopic world. One of the first people to pay attention to the special behavior of the microscopic world was Louis de Broglie. He asked the question: If electromagnetic radiation can have particle-like character, can electrons and other submicroscopic particles exhibit wavelike character? In his doctoral dissertation, de Broglie extended the wave—particle duality of light that Einstein used to resolve the photoelectric-effect paradox to material particles.

This is called the de Broglie wavelength. Although these two symbols appear nearly identical, they mean very different things. Shortly after de Broglie proposed the wave nature of matter, two scientists at Bell Laboratories, C. Davisson and L. Germerdemonstrated experimentally that electrons can exhibit wavelike behavior by showing an interference pattern for electrons travelling through a regular atomic pattern in a crystal.

The regularly spaced atomic layers served as slits, as used in other interference experiments. Figure 6. It is strikingly similar to the interference patterns for light shown in Electromagnetic Energy for light passing through two closely spaced, narrow slits.

The wave—particle duality of matter can be seen in Figure 6. Initially, when only a few electrons have been recorded, they show clear particle-like behavior, having arrived in small localized packets that appear to be random. As more and more electrons arrived and were recorded, a clear interference pattern that is the hallmark of wavelike behavior emerged.

Intro to Quantum Theory - Chemistry (CHEM101)

Thus, it appears that while electrons are small localized particles, their motion does not follow the equations of motion implied by classical mechanics, but instead it is governed by some type of a wave equation. Thus the wave—particle duality first observed with photons is actually a fundamental behavior intrinsic to all quantum particles. View the Dr. Quantum — Double Slit Experiment cartoon for an easy-to-understand description of wave—particle duality and the associated experiments.

This is a small value, but it is significantly larger than the size of an electron in the classical particle view.Why did the model work so well describing hydrogen and one-electron ions, but could not correctly predict the emission spectrum for helium or any larger atoms? To answer these questions, scientists needed to completely revise the way they thought about matter.

We know how matter behaves in the macroscopic world—objects that are large enough to be seen by the naked eye follow the rules of classical physics. A billiard ball moving on a table will behave like a particle: It will continue in a straight line unless it collides with another ball or the table cushion, or is acted on by some other force such as friction.

In other words, the ball is moving in a classical trajectory. This is the typical behavior of a classical object. Figure 1. An interference pattern on the water surface is formed by interacting waves. The waves are caused by reflection of water from the rocks. When waves interact with each other, they show interference patterns that are not displayed by macroscopic particles such as the billiard ball.

For example, interacting waves on the surface of water can produce interference patters similar to those shown on Figure 1. This is a case of wave behavior on the macroscopic scale, and it is clear that particles and waves are very different phenomena in the macroscopic realm.

As technological improvements allowed scientists to probe the microscopic world in greater detail, it became increasingly clear by the s that very small pieces of matter follow a different set of rules from those we observe for large objects. The unquestionable separation of waves and particles was no longer the case for the microscopic world.

One of the first people to pay attention to the special behavior of the microscopic world was Louis de Broglie. He asked the question: If electromagnetic radiation can have particle-like character, can electrons and other submicroscopic particles exhibit wavelike character? In his doctoral dissertation, de Broglie extended the wave—particle duality of light that Einstein used to resolve the photoelectric-effect paradox to material particles.

This is called the de Broglie wavelength. Although these two symbols are identical, they mean very different things. Figure 2. If an electron is viewed as a wave circling around the nucleus, an integer number of wavelengths must fit into the orbit for this standing wave behavior to be possible.

Since the de Broglie expression relates the wavelength to the momentum and, hence, velocity, this implies:.Why did the model work so well describing hydrogen and one-electron ions, but could not correctly predict the emission spectrum for helium or any larger atoms?

To answer these questions, scientists needed to completely revise the way they thought about matter. We know how matter behaves in the macroscopic world—objects that are large enough to be seen by the naked eye follow the rules of classical physics.

A billiard ball moving on a table will behave like a particle: It will continue in a straight line unless it collides with another ball or the table cushion, or is acted on by some other force such as friction. In other words, the ball is moving in a classical trajectory. This is the typical behavior of a classical object. When waves interact with each other, they show interference patterns that are not displayed by macroscopic particles such as the billiard ball.

For example, interacting waves on the surface of water can produce interference patters similar to those shown on Figure 1. This is a case of wave behavior on the macroscopic scale, and it is clear that particles and waves are very different phenomena in the macroscopic realm.

6.3: Development of Quantum Theory

As technological improvements allowed scientists to probe the microscopic world in greater detail, it became increasingly clear by the s that very small pieces of matter follow a different set of rules from those we observe for large objects. The unquestionable separation of waves and particles was no longer the case for the microscopic world. One of the first people to pay attention to the special behavior of the microscopic world was Louis de Broglie. He asked the question: If electromagnetic radiation can have particle-like character, can electrons and other submicroscopic particles exhibit wavelike character?

In his doctoral dissertation, de Broglie extended the wave—particle duality of light that Einstein used to resolve the photoelectric-effect paradox to material particles. This is called the de Broglie wavelength. Although these two symbols are identical, they mean very different things. Since the de Broglie expression relates the wavelength to the momentum and, hence, velocity, this implies:.

Classical angular momentum L for a circular motion is equal to the product of the radius of the circle and the momentum of the moving particle p. Shortly after de Broglie proposed the wave nature of matter, two scientists at Bell Laboratories, C.

Davisson and L. Germerdemonstrated experimentally that electrons can exhibit wavelike behavior by showing an interference pattern for electrons travelling through a regular atomic pattern in a crystal. The regularly spaced atomic layers served as slits, as used in other interference experiments.

Figure 4 shows an interference pattern. It is strikingly similar to the interference patterns for light shown in Figure 5 in Chapter 6. The wave—particle duality of matter can be seen in Figure 4 by observing what happens if electron collisions are recorded over a long period of time. Initially, when only a few electrons have been recorded, they show clear particle-like behavior, having arrived in small localized packets that appear to be random.Why did the model work so well describing hydrogen and one-electron ions, but could not correctly predict the emission spectrum for helium or any larger atoms?

To answer these questions, scientists needed to completely revise the way they thought about matter. We know how matter behaves in the macroscopic world—objects that are large enough to be seen by the naked eye follow the rules of classical physics. A billiard ball moving on a table will behave like a particle: It will continue in a straight line unless it collides with another ball or the table cushion, or is acted on by some other force such as friction.

In other words, the ball is moving in a classical trajectory. This is the typical behavior of a classical object. When waves interact with each other, they show interference patterns that are not displayed by macroscopic particles such as the billiard ball. This is a case of wave behavior on the macroscopic scale, and it is clear that particles and waves are very different phenomena in the macroscopic realm.

The waves are caused by reflection of water from the rocks. As technological improvements allowed scientists to probe the microscopic world in greater detail, it became increasingly clear by the s that very small pieces of matter follow a different set of rules from those we observe for large objects.

The unquestionable separation of waves and particles was no longer the case for the microscopic world.

6 3 development of quantum theory u2013 chemistry

One of the first people to pay attention to the special behavior of the microscopic world was Louis de Broglie. He asked the question: If electromagnetic radiation can have particle-like character, can electrons and other submicroscopic particles exhibit wavelike character? In his doctoral dissertation, de Broglie extended the wave—particle duality of light that Einstein used to resolve the photoelectric-effect paradox to material particles.

This is called the de Broglie wavelength. Although these two symbols are identical, they mean very different things. Since the de Broglie expression relates the wavelength to the momentum and, hence, velocity, this implies:.

Classical angular momentum L for a circular motion is equal to the product of the radius of the circle and the momentum of the moving particle p. Shortly after de Broglie proposed the wave nature of matter, two scientists at Bell Laboratories, C. Davisson and L. Germerdemonstrated experimentally that electrons can exhibit wavelike behavior by showing an interference pattern for electrons travelling through a regular atomic pattern in a crystal.

The regularly spaced atomic layers served as slits, as used in other interference experiments. The electrons pass through very closely spaced slits, forming an interference pattern, with increasing numbers of electrons being recorded from the left image to the right.

As more electrons arrive, a wavelike interference pattern begins to emerge. Note that the probability of the final electron location is still governed by the wave-type distribution, even for a single electron, but it can be observed more easily if many electron collisions have been recorded. The wave—particle duality of matter can be seen by observing what happens if electron collisions are recorded over a long period of time.

Initially, when only a few electrons have been recorded, they show clear particle-like behavior, having arrived in small localized packets that appear to be random. As more and more electrons arrived and were recorded, a clear interference pattern that is the hallmark of wavelike behavior emerged. Thus the wave—particle duality first observed with photons is actually a fundamental behavior intrinsic to all quantum particles.

View the Dr. Quantum — Double Slit Experiment cartoon for an easy-to-understand description of wave—particle duality and the associated experiments. If an electron travels at a velocity of 1. This is a small value, but it is significantly larger than the size of an electron in the classical particle view.


Replies to “6 3 development of quantum theory u2013 chemistry”

Leave a Reply

Your email address will not be published. Required fields are marked *