History of the Atomic Theory

What experiment did Schrodinger do to test his hypothesis and develop his model? Explain how the experiment works.

He did the famous experiment called the "Schrodinger's Cat." In this experiment, a cat is in a box with a vial of poison. If an atom inside the box decays, the vial breaks. The atom is superposed in decay and non-decay states until it is observed. The cat is also observed and found in alive or dead states.

What experiment did Thomson do to test his hypothesis and develop his model? Explain how the experiment works.

He experimented with cathode ray tubes. It showed that all atoms contain tiny negatively charged subatomic particles or electrons. It worked because It proposed the plum pudding model of the atom, which had negatively-charged electrons embedded within a positively-charged.

What are the 5 key points of Dalton's theory?

1. All matter is composed of extremely small particles called atoms. 2. Atoms of a given element are identical in size, mass and other properties. Atoms of different elements differ in size, mass and other properties. 3. Atoms cannot be subdivided, created, or destroyed. 4. Atoms of different elements can combine in simple whole numbers ratios to form chemical compounds. 5. In chemical reactions, atoms are combined, separated, or rearranged.

What experiment did Bohr do to test his hypothesis and develop his model? How was he able to improve on Rutherford's model?

Bohr used Quantum physics. The atom consists of heavy, positively charged components (protons and neutrons) that are circled at a far distance by lighter electrons. Their theory proposed that this was possible, defying traditional physics because of "quanta," or energy particles, that keep it bonded together. Electrons follow particular orbits based on the "quantum of action," and electrostatic forces rather than gravity. In conclusion- electrons float on orbital rings rather than randomly around the nucleus

Who was Ernest Rutherford and where does his theory fit in the timeline of history?

Ernest Rutherford(1871-1937) was a New Zealand-born British physicist who came to be known as the father of nuclear physics. He proposed the theory that atoms consist mostly of empty space, with its mass concentrated in a central positively charged nucleus. He also discovered the two types of radiation, alpha and beta. His theory fits right into the time where people were starting to speculate about the model of an atom.

Who was Erwin Schrodinger and where does his theory fit in the timeline of history?

Erwin Schrodinger(1887-1961) was an Austrian-Irish physicist who used mathematical equations to describe the likelihood of finding an electron in a certain position.

Explain Bohr's model of the atom.

Essentially, it was a primitive model of a hydrogen atom; advancing Rutherford's model by arranging electrons in rings around a dense nucleus, rather than floating around randomly inside a field.

What experiment did Rutherford do to test his hypothesis and develop his model? Explain how the Gold Foil experiment works.

He tested his hypothesis with an experiment called the gold foil which was to put a thin sheet of gold and used alpha particles in between to see how it would react, and with that he discovered that atoms has mostly empty space with a small density of positive charged nucleus. Based on the results he had gotten, he proposed the nuclear model of the atom.

What experiment did de Broglie do to test his hypothesis and develop his model? Explain how the experiment works.

He was a theorist so he had no experiment himself. He just built on a proposition that was created 20 years before.

Explain Chadwick's model of the atom. How did his work help further our understanding of the atom?

His atomic model was known as the quantum mechanical model. James Chadwick bombarded beryllium atoms with alpha particles. An unknown radiation was produced. He interpreted this radiation as being composed of particles with a neutral electrical charge and the approximate mass of a proton.

What experiment did Heisenberg do to test his hypothesis and develop his model? Explain how the experiment works.

His hypothesis was that the use of probabilistic formulations in atomic theory resulted not from ignorance but from the necessarily nondeterministic relationship between the variables. He considered trying to measure the position of an electron with a gamma ray microscope. The high-energy photon used to illuminate the electron would give it a kick, changing its momentum in an uncertain way. A higher resolution microscope would require higher energy light, giving an even bigger kick to the electron. The more precisely one tried to measure the position, the more uncertain the momentum would become, and vice versa, Heisenberg reasoned. This uncertainty is a fundamental feature of quantum mechanics, not a limitation of any particular experimental apparatus.

Explain Schrodinger's model of the atom.

His model of the atom was called the quantum mechanical model if the atom

Explain Thomson's model of the atom.

His model of the atom was was one they call the "raisin or plum pudding" model. It was a sphere filled with positively charged fluid with negatively charged particles floating in the fluid. He did not predict that the electrons would move though.

What experiments did Dalton do to test his theory?

In 1803 Dalton discovered that oxygen combined with either one or two volumes of nitric oxide in closed vessels over water provided important experimental evidence for his atomic ideas. In his book A New System of Chemical Philosophy, Dalton also wrote about his experiments proving that atoms combine in simple ratios. Which means that the molecules of an element are always made up of the same proportions, except water. Dalton also believed atomic theory could explain why water absorbed different gases in different proportions. For example, he found that water absorbed carbon dioxide better than it absorbed nitrogen.

Who was JJ Thomson and where does his theory fit in the timeline of history?

JJ Thomson(1856-1940) was a British physicist who discovered the electron.

Who was John Dalton and where does he fit in the timeline of history?

John Dalton(1766-1844) was a schoolteacher who was known for introducing the atomic theory into chemistry.

What are the pros and cons of Thomson's model?

Pros: It was the first atomic model which was simple and visual.It had electrons and protons scattered in the atom like a plum pudding or seeds in watermelon. Cons: It did not mention the presence of the nucleus in an atom. The model says the positive charge is uniformly distributed throughout the atom. This is highly untrue. We know the positive charge is centered in the atoms. It failed to explain Rutherford's gold scattering experiment. The model was abandoned as it was unable to explain the deflection of alpha particles when projected on gold foils.

What are the pros and cons of Rutherford's model?

Pros: Positively charged nucleus with negatively charged electrons orbiting it. Had protons, neutrons, and electrons. Parts of it could be verified by the gold foil experiment. Cons: Didn't explain why the electrons remained in orbit.

Who was Werner Heisenberg and where does his theory fit in the timeline of history?

Werner Heisenberg(1901-1976) was a German physicist and philosopher who discovered a way to formulate quantum mechanics in terms of matrices.

Explain de Broglie's contributions to atomic theory. How did his work help further our understanding of the atom?

In 1924, he elaborated on Einstein's thesis on the idea that light at a low enough frequency will be seen as particles. He explained the reason for that was how electron waves in atoms were the reason for this, since a wave going against another wave cancels it, that would be the same in the waves of electrons and light. He helped us understand the properties of electrons. He suggested this for all matter.

What experiment did Chadwick do to test his hypothesis and develop his model? Explain how the experiment works.

In 1930, it was discovered that Beryllium, when bombarded by alpha particles, emitted a very energetic stream of radiation. This stream was originally thought to be gamma radiation. However, further investigations into the properties of the radiation revealed contradictory results. Like gamma rays, these rays were extremely penetrating and since they were not deflected upon passing through a magnetic field, neutral. However, unlike gamma rays, these rays did not discharge charged electroscopes (the photoelectric effect)

Who was James Chadwick and where does his theory fit in the timeline of history?

James Chadwick(1891-1974) was a British physicist who discovered the neutron.

Who was Louis de Broglie and where does his theory fit in the timeline of history?

Louis de Broglie(1892-1987) was a French physicist and aristocrat who made groundbreaking contributions to quantum theory. In his 1924 PhD thesis, he postulated the wave nature of electrons and suggested that all matter has wave properties.

Who was Neils Bohr and where does his theory fit in the timeline of history?

Neils Bohr(1885-1962) was a Danish physicist who made foundational contributions to understanding atomic structure and quantum theory. In 1913, he proposed that electrons travel in defined circular orbits around the nucleus. Electrons can jump from one orbit to another by emitting or absorbing energy.

What are the pros and cons of de Broglie's model?

Pros: Gives more of a logical addition to a theory of Einstein. Also gives better understanding of what atoms do. Cons: No experimental evidence of his theory being true.

What are the pros and cons of Dalton's model?

Pros: His math was correct and he introduced the idea of atoms. Cons: It didn't explain other things like the electricity of an atom or how much it weighed.

What are the pros and cons of Schrodinger's model?

Pros: It consisted of mathematical equations known as wave functions that satisfy the requirements placed on the behavior of electrons. Cons: It is difficult to imagine a physical model of electrons as waves.

What are the pros and cons of Bohr's model?

Pros: It explained line emission spectra of Hydrogen, very well. Cons: It did not explain how atoms could be stable and the electron not spiral into the nucleus as it emitted EMR.

What are the pros and cons of Chadwick's model?

Pros: It fixed the issue with the planetary model discrepancy with atomic number and mass. Cons: Didn't describe the location of electrons other than outside the nucleus.

What are the pros and cons of Heisenberg's model?

Pros: The power and varieties of research purposes it withholds. Cons: Very expensive.

Explain Rutherford's model of the atom.

Rutherford's model shows that an atom is mostly empty space, with electrons orbiting a fixed, positively charged nucleus in set, predictable paths. It is, in many ways, the classical model of the atom. It is no longer accepted as an accurate model today, however.

Explain Heisenberg's contributions to atomic theory. How did his work help further our understanding of the atom?

The atomic theory the applications of it which resulted especially in the discovery of allotropic forms of hydrogen.