Who was the first scientist to propose that an object would emit only certain amounts of energy?
Chemistry Test 4
| Question | Answer |
|---|---|
| Who was the first scientist to propose that an object could emit only certain amounts of energy? | Planck |
| Who proposed a model that successfully explained the photoelectric effect? | Einstein |
Which scientist first proposed that the electron in the hydrogen atom?
The discovery of the electron and radioactivity in the late 19th century led to different models being proposed for the atom's structure. In 1913, Niels Bohr proposed a theory for the hydrogen atom, based on quantum theory that some physical quantities only take discrete values.
Who developed an empirical equation from which the wavelengths of lines in the spectrum of hydrogen atoms can be calculated?
Niels Bohr Bohr's model of the hydrogen atom, proposed by Niels Bohr in 1913, was the first quantum model that correctly explained the hydrogen emission spectrum. Bohr's model combines the classical mechanics of planetary motion with the quantum concept of photons.
How did Bohr fix Rutherford model?
To remedy the stability problem, Bohr modified the Rutherford model by requiring that the electrons move in orbits of fixed size and energy. The energy of an electron depends on the size of the orbit and is lower for smaller orbits. Radiation can occur only when the electron jumps from one orbit to another.
How did Bohr discover his model?
It was while Bohr was working in England in 1913 that he developed this atomic model. He developed the model after studying the way glowing, hot hydrogen gives off light. When an incandescent light bulb is lit, it gives off all the different wavelengths of light.
What did J.J. Thomson discover?
On April 30, 1897, British physicist J.J. Thomson announced his discovery that atoms were made up of smaller components. This finding revolutionized the way scientists thought about the atom and had major ramifications for the field of physics.
What was J.J. Thomson’s atomic model?
J.J. Thomson's experiments with cathode ray tubes showed that all atoms contain tiny negatively charged subatomic particles or electrons. Thomson proposed the plum pudding model of the atom, which had negatively-charged electrons embedded within a positively-charged "soup."
What is Rydberg’s equation used for?
The Rydberg formula is a mathematical formula used to predict the wavelength of light resulting from an electron moving between energy levels of an atom.
What is Rydberg equation explain the terms?
The Rydberg formula is the mathematical formula to compute the wavelength of light. When an electron changes from one atomic orbit to another one, then the energy of electron changes. When the electron changes from one orbit with high energy to a lower energy state, then the photon of light is created.
What was Ernest Rutherford atomic theory?
Ernest Rutherford found that the atom is mostly empty space, with nearly all of its mass concentrated in a tiny central nucleus. The nucleus is positively charged and surrounded at a great distance by the negatively charged electrons.
What was JJ Thomson atomic model?
J.J. Thomson's experiments with cathode ray tubes showed that all atoms contain tiny negatively charged subatomic particles or electrons. Thomson proposed the plum pudding model of the atom, which had negatively-charged electrons embedded within a positively-charged "soup."
What did Schrodinger and Heisenberg discover?
In the 1920s, physicists were trying to apply Planck's concept of energy quanta to the atom and its constituents. By the end of the decade Erwin Schrödinger and Werner Heisenberg had invented the new quantum theory of physics.
What did James Chadwick discover?
In 1932, Chadwick made a fundamental discovery in the domain of nuclear science: he proved the existence of neutrons – elementary particles devoid of any electrical charge.
What did Robert A Millikan discover?
In 1910 Robert Millikan succeeded in precisely determining the magnitude of the electron's charge. Small electrically charged drops of oil were suspended between two metal plates where they were subjected to the downward force of gravity and the upward attraction of an electrical field.
What Rydberg discovered?
Johannes Rydberg was a Swedish physicist who attempted to find a mathematical relationship between one spectral line and the next of certain elements. He eventually discovered there was an integer relationship between the wavenumbers of successive lines.
How did Bohr explain the Rydberg equation?
To explain the hydrogen atom luminescence spectrum, Bohr said that light of frequency νif is produced when an electron goes from an orbit with n = i (“i” represents “initial”) to a lower energy orbit with n = f (“f” represents “final”), with i > f.
What was Robert Millikan’s atomic theory?
Robert Millikan Atomic Theory Millikan's work demonstrated that electrons did have a discrete, quantifiable charge. Thomson had also already calculated the charge-to-mass ratio of an electron, so once Millikan was able to measure the elementary charge, the mass of an electron could also be calculated.
What is Erwin Schrödinger known for?
Erwin Schrödinger is best known for the Schrödinger equation, which describes the evolution of the wave function, a quantity that describes the wave properties of a particle.
What did Rutherford and Chadwick discover?
Chadwick was able to continue to work on radioactivity, now with more sophisticated apparatus than tin foil and toothpaste. In 1923, Chadwick was appointed assistant director of Cavendish Laboratory. Rutherford had discovered the atomic nucleus in 1911, and had observed the proton in 1919.
What did JJ Thomson discover?
On April 30, 1897, British physicist J.J. Thomson announced his discovery that atoms were made up of smaller components. This finding revolutionized the way scientists thought about the atom and had major ramifications for the field of physics.
What is Millikan known for?
In 1910 Robert Millikan succeeded in precisely determining the magnitude of the electron's charge. Small electrically charged drops of oil were suspended between two metal plates where they were subjected to the downward force of gravity and the upward attraction of an electrical field.
Who discovered Rydberg Polarons?
physicist Johannes Rydberg In Rydberg atoms, one or more electrons are excited with a precise amount of energy so that they orbit far from the atom's nucleus. Rydberg atoms can be described with simple rules written down more than a century ago by Swedish physicist Johannes Rydberg.
What is Rydberg known for?
Rydberg is best known for his theoretical studies of spectral series. Using wavenumbers instead of wavelengths in his calculations, he was able to arrive at a relatively simple expression that related the various lines in the spectra of chemical elements.
What does Bohr’s model explain?
Bohr model of the atom. In the Bohr model of the atom, electrons travel in defined circular orbits around the nucleus. The orbits are labeled by an integer, the quantum number n. Electrons can jump from one orbit to another by emitting or absorbing energy.
Did Millikan and Rutherford come first?
Two thousand years later, Dalton proved Democritus was correct. Shortly after that, electrons were discovered by Thomson, the nucleus was discovered by Rutherford and the charge of an electron was measured by Millikan.
What did Schrödinger and Heisenberg discover?
In the 1920s, physicists were trying to apply Planck's concept of energy quanta to the atom and its constituents. By the end of the decade Erwin Schrödinger and Werner Heisenberg had invented the new quantum theory of physics.
What did Schrödinger discover?
Erwin Schrodinger: Equation In 1926, Schrodinger discovered one of the foundations of quantum mechanics, the famous Erwin Schrodinger equation (also known as Schrodinger's equation). He used differential equations to describe how the quantum state of a physical system changes over time.
What did Sir James Chadwick discover?
In 1927 he was elected a Fellow of the Royal Society. In 1932, Chadwick made a fundamental discovery in the domain of nuclear science: he proved the existence of neutrons – elementary particles devoid of any electrical charge.
What was James Chadwick theory?
James Chadwick discovered that atoms consisted not only of protons and electrons but also neutrons. Chadwick discovered the neutron, a neutral subatomic particle that has approximately the same mass as a proton. Neutrons occupy the nucleus of the atom.
What did Marie Curie discover?
RadiumPolonium Marie Curie/Discovered Marie Curie is remembered for her discovery of radium and polonium, and her huge contribution to finding treatments for cancer.