romikgosai/squad_modified_2 huggingface dataset:
Large masses, such as ice sheets or glaciers, can depress the crust of the Earth into the mantle. The depression usually totals a third of the ice sheet or glacier's thickness. After the ice sheet or glacier melts, the mantle begins to flow back to its original position, pushing the crust back up. This post-glacial rebound, which proceeds very slowly after the melting of the ice sheet or glacier, is currently occurring in measurable amounts in Scandinavia and the Great Lakes region of North America.

Q1: Where is post-glacial rebound occuring most?
A1: Scandinavia and the Great Lakes region of North America.
Q2: What has the ability to depress the crust of the Earth into the mantle?
A2: Large masses, such as ice sheets or glaciers
Q3: With what speed does post-glacial rebound occur?
A3: very slowly
Q4: How much of a glacier's thickness is usually involved during crust depression into the mantle?
A4: a third of the ice sheet or glacier's thickness
First recognized in 1900 by Max Planck, it was originally the proportionality constant between the minimal increment of energy, E, of a hypothetical electrically charged oscillator in a cavity that contained black body radiation, and the frequency, f, of its associated electromagnetic wave. In 1905 the value E, the minimal energy increment of a hypothetical oscillator, was theoretically associated by Einstein with a "quantum" or minimal element of the energy of the electromagnetic wave itself. The light quantum behaved in some respects as an electrically neutral particle, as opposed to an electromagnetic wave. It was eventually called the photon.

Q1: What is considered the minimal energy increment of a hypothetical oscillator?
A1: value E
Q2: In what year was the value E associated by Einstein with quantum theories of energy?
A2: 1905
Q3: Who discovered an association between the value E and quantum energy?
A3: Einstein
Q4: What did the light quantum behave the same as in laboratory experiments?
A4: neutral particle
Q5: What type of charge did a particle have that behaved similarly to light quantum energy?
A5: neutral
Q6: What is energy abbreviated to in science?
A6: E
Q7: What is frequency also known as in science?
A7: f
Q8: What term describes a small amount of element?
A8: quantum
Q9: What did the light quantum, in some ways, behave as?
A9: an electrically neutral particle
Q10: What was later termed the photon?
A10: The light quantum
Q11: When did Max Planck first recognize the value of the Planck constant?
A11: 1900
Q12: Which scientist associated the Planck constant with a quantum five years after Planck's recognition?
A12: Einstein
Q13: Instead of an electromagnetic wave, what did the light quantum behave as in some regards?
A13: an electrically neutral particle
Q14: What is the simple name given to the light quantum today?
A14: the photon
Classical statistical mechanics requires the existence of h (but does not define its value). Eventually, following upon Planck's discovery, it was recognized that physical action cannot take on an arbitrary value. Instead, it must be some multiple of a very small quantity, the "quantum of action", now called the Planck constant. Classical physics cannot explain this fact. In many cases, such as for monochromatic light or for atoms, this quantum of action also implies that only certain energy levels are allowed, and values in between are forbidden.

Q1: What does classical statistics mechanics not define the value of?
A1: h
Q2: What is required to exist in classical statistics mechanics?
A2: h
Q3: After Planck's findings, what was determined could not take on an arbitrary value?
A3: physical action
Q4: What is the "quantum of action" called?
A4: the Planck constant
Q5: What does the Planck Constant refer to?
A5: quantum of action
Q6: Classical statistical mechanics requires the existence of what?
A6: h
Q7: What was realized after Planck's discovery?
A7: that physical action cannot take on an arbitrary value
Q8: What is the Planck constant formerly known as?
A8: quantum of action
Q9: Regarding atoms, what does the Planck constant imply?
A9: that only certain energy levels are allowed
Q10: Regarding atoms, what are values in between certain energy levels considered by the Planck constant?
A10: forbidden
Q11: Following Planck's discovery, what was realized about values of physical action?
A11: physical action cannot take on an arbitrary value
Q12: The Planck constant initially was given what name?
A12: the "quantum of action"
Q13: How is the proportional nature of the Planck constant explained?
A13: Classical physics cannot explain this fact
Q14: For certain cases of light or atoms, what does the quantum of action yield?
A14: only certain energy levels are allowed, and values in between are forbidden.
Equivalently, the smallness of the Planck constant reflects the fact that everyday objects and systems are made of a large number of particles. For example, green light with a wavelength of 555 nanometres (the approximate wavelength to which human eyes are most sensitive) has a frequency of 7014540000000000000♠540 THz (7014540000000000000♠540×1012 Hz). Each photon has an energy E = hf = 6981358000000000000♠3.58×10−19 J. That is a very small amount of energy in terms of everyday experience, but everyday experience is not concerned with individual photons any more than with individual atoms or molecules. An amount of light compatible with everyday experience is the energy of one mole of photons; its energy can be computed by multiplying the photon energy by the Avogadro constant, NA ≈ 7023602200000000000♠6.022×1023 mol−1. The result is that green light of wavelength 555 nm has an energy of 7005216000000000000♠216 kJ/mol, a typical energy of everyday life.

Q1: What are common things like furniture and stationary objects actually made of?
A1: particles
Q2: Which light wavelength is the human eye most sensitive to?
A2: 555 nanometres
Q3: What color of light is the human eye most sensitive to?
A3: green
Q4: What does the smallness of the Planck constant show?
A4: the fact that everyday objects and systems are made of a large number of particles
Q5: At about what wavelength of light are human eyes most sensitive?
A5: 555 nanometres
Q6: What frequency does green light with a wavelength of 555 nanmetres have?
A6: 7014540000000000000♠540 THz
Q7: How is the energy from one mole of photos computed?
A7: by multiplying the photon energy by the Avogadro constant
Q8: How much energy does a green light of wavelength 555 nm contain?
A8: 7005216000000000000♠216 kJ/mol
Q9: What is the wavelength of light to which human eyes are most sensitive?
A9: 555 nanometres
Q10: What is the frequency of the light to which the human eye is most sensitive?
A10: 7014540000000000000♠540 THz
Q11: What is the energy of a photon?
A11: 6981358000000000000♠3.58×10−19 J
Q12: How much energy is contained in the light to which human eyes are most sensitive?
A12: 7005216000000000000♠216 kJ/mol
In the last years of the nineteenth century, Planck was investigating the problem of black-body radiation first posed by Kirchhoff some forty years earlier. It is well known that hot objects glow, and that hotter objects glow brighter than cooler ones. The electromagnetic field obeys laws of motion similarly to a mass on a spring, and can come to thermal equilibrium with hot atoms. The hot object in equilibrium with light absorbs just as much light as it emits. If the object is black, meaning it absorbs all the light that hits it, then its thermal light emission is maximized.

Q1: What type of radiation was Planck studying in the late 19th century?
A1: black-body
Q2: How many years prior to Planck's study had the scientific community first discussed black body radiation?
A2: forty
Q3: What scientist first studied black body radiation?
A3: Kirchhoff
Q4: What is required for the electromagnetic field to come to thermal equilibrium?
A4: hot atoms
Q5: What does a hot object in equilibrium absorb as much as it emits?
A5: light
Q6: What was Planck studying in the last part of the nineteenth century?
A6: the problem of black-body radiation
Q7: Who posed the problem of black-body radiation?
A7: Kirchhoff
Q8: Cooler objects glow less than objects that are what?
A8: hotter
Q9: What does a black object do to any of the light that hits it?
A9: it absorbs all the light
Q10: What is maximized as a result of a black object absorbing all the light that hits it?
A10: thermal light emission
Q11: Planck studied what problem posed originally by Kirchhoff?
A11: black-body radiation
Q12: If an object is black, what is known about its thermal light emission?
A12: its thermal light emission is maximized.
Q13: What is known about the light absorption of a hot object in equilibrium with light?
A13: absorbs just as much light as it emits
Q14: Electromagnetic fields obey what laws?
A14: laws of motion
The assumption that black-body radiation is thermal leads to an accurate prediction: the total amount of emitted energy goes up with the temperature according to a definite rule, the Stefan–Boltzmann law (1879–84). But it was also known that the colour of the light given off by a hot object changes with the temperature, so that "white hot" is hotter than "red hot". Nevertheless, Wilhelm Wien discovered the mathematical relationship between the peaks of the curves at different temperatures, by using the principle of adiabatic invariance. At each different temperature, the curve is moved over by Wien's displacement law (1893). Wien also proposed an approximation for the spectrum of the object, which was correct at high frequencies (short wavelength) but not at low frequencies (long wavelength). It still was not clear why the spectrum of a hot object had the form that it has (see diagram).

Q1: What do scientists assume black body radiation is?
A1: thermal
Q2: What kind of prediction does the assumption that black body radiation is thermal lead to?
A2: accurate
Q3: What type of changes in the light a hot object emits as the object's temperature changes?
A3: colour
Q4: What law describes the changes in light emitted by a hot object?
A4: Stefan–Boltzmann law
Q5: What assumption that black-body radiation is what leads to an accurate prediction?
A5: thermal
Q6: What does the Stefan-Boltzmann law state?
A6: the total amount of emitted energy goes up with the temperature according to a definite rule
Q7: What about a hot object changes with the temperature?
A7: the colour of the light
Q8: What color is hotter than "red hot"?
A8: white hot
Q9: What did Wilhelm Wien discover?
A9: the mathematical relationship between the peaks of the curves at different temperatures
Q10: What rule predicts that emitted energy increases with temperature?
A10: the Stefan–Boltzmann law
Q11: What characteristic of the light emitted by a hot object changes with temperature?
A11: the colour of the light given off
Q12: Who discovered the mathematical relationship between peaks and curves of light at different temperatures?
A12: Wilhelm Wien
Q13: The rule that adjust the curve at different temperatures is known as what?
A13: Wien's displacement law
Q14: Wien's spectrum model could not predict accurate at what end of the spectrum?
A14: at low frequencies (long wavelength)
Prior to Planck's work, it had been assumed that the energy of a body could take on any value whatsoever – that it was a continuous variable. The Rayleigh–Jeans law makes close predictions for a narrow range of values at one limit of temperatures, but the results diverge more and more strongly as temperatures increase. To make Planck's law, which correctly predicts blackbody emissions, it was necessary to multiply the classical expression by a complex factor that involves h in both the numerator and the denominator. The influence of h in this complex factor would not disappear if it were set to zero or to any other value. Making an equation out of Planck's law that would reproduce the Rayleigh–Jeans law could not be done by changing the values of h, of the Boltzmann constant, or of any other constant or variable in the equation. In this case the picture given by classical physics is not duplicated by a range of results in the quantum picture.

Q1: Before Planck, it was assumed that the energy of a body could take on what value?
A1: any
Q2: The Rayleigh-Jeans law makes close predictions for what amount of values?
A2: a narrow range
Q3: What does Planck's law correctly predict?
A3: blackbody emissions
Q4: In making Planck's law, what was in both the numerator and denominator of the formula that was used?
A4: h
Q5: Planck's work disproved what assumption?
A5: that the energy of a body could take on any value whatsoever
Q6: What rule predicted narrow range of energy values at lower temperatures?
A6: The Rayleigh–Jeans
Q7: Planck's law involved what necessary mathematical step to correctly predict blackbody emission?
A7: multiply the classical expression by a complex factor that involves h in both the numerator and the denominator
Q8: Changing values of n, the Boltzmann constant, or other variables resulted in learning what about Planck's law?
A8: Making an equation out of Planck's law that would reproduce the Rayleigh–Jeans law could not be done
Q9: The disparity between Planck's law and the Rayleigh-Jeans law led to what conclusion?
A9: the picture given by classical physics is not duplicated by a range of results in the quantum picture
The black-body problem was revisited in 1905, when Rayleigh and Jeans (on the one hand) and Einstein (on the other hand) independently proved that classical electromagnetism could never account for the observed spectrum. These proofs are commonly known as the "ultraviolet catastrophe", a name coined by Paul Ehrenfest in 1911. They contributed greatly (along with Einstein's work on the photoelectric effect) to convincing physicists that Planck's postulate of quantized energy levels was more than a mere mathematical formalism. The very first Solvay Conference in 1911 was devoted to "the theory of radiation and quanta". Max Planck received the 1918 Nobel Prize in Physics "in recognition of the services he rendered to the advancement of Physics by his discovery of energy quanta".

Q1: Einstein and what other two individuals revisited the black-body problem in 1905?
A1: Rayleigh and Jeans
Q2: Who came up with the term, "ultraviolet catastrophe"?
A2: Paul Ehrenfest
Q3: When did Paul Ehrenfest come up with the name "ultraviolet catastrophe"?
A3: 1911
Q4: When was the first Solvay Conference held?
A4: 1911
Q5: Who received the Nobel Prize in Physics in 1918?
A5: Max Planck
Q6: What did Rayleigh & Jeans and Einstein prove independently in 1905?
A6: classical electromagnetism could never account for the observed spectrum
Q7: What name did Paul Ehrenfest give to the proofs from Einstein and Rayleigh & Jeans?
A7: the "ultraviolet catastrophe"
Q8: When was the first Solvay Conference held?
A8: 1911
Q9: What was the topic of the first Solvay Conference?
A9: "the theory of radiation and quanta"
Q10: In what year did Planck receive the Nobel Prize in Physics for his discovery of energy quanta?
A10: 1918
The photoelectric effect is the emission of electrons (called "photoelectrons") from a surface when light is shone on it. It was first observed by Alexandre Edmond Becquerel in 1839, although credit is usually reserved for Heinrich Hertz, who published the first thorough investigation in 1887. Another particularly thorough investigation was published by Philipp Lenard in 1902. Einstein's 1905 paper discussing the effect in terms of light quanta would earn him the Nobel Prize in 1921, when his predictions had been confirmed by the experimental work of Robert Andrews Millikan. The Nobel committee awarded the prize for his work on the photo-electric effect, rather than relativity, both because of a bias against purely theoretical physics not grounded in discovery or experiment, and dissent amongst its members as to the actual proof that relativity was real.

Q1: Who first observed the photoelectric effect?
A1: Alexandre Edmond Becquerel
Q2: When was the photoelectric effect first observed?
A2: 1839
Q3: Who published the first thorough investigation of the photoelectric effect?
A3: Heinrich Hertz
Q4: Who received the Nobel Prize in 1921 for his work on the photoelectric effect?
A4: Einstein
Q5: What did Einstein with the 1921 Nobel Prize for?
A5: his work on the photo-electric effect
Q6: What is the photoelectric effect?
A6: the emission of electrons (called "photoelectrons") from a surface when light is shone on it
Q7: Who first observed the photoelectric effect?
A7: Alexandre Edmond Becquerel
Q8: Einstein's paper on the photoelectric effect earned him the Nobel Prize in what year?
A8: 1921
Q9: Einstein's photoelectric effect work was rewards as opposed to his work on what other topic?
A9: relativity
Prior to Einstein's paper, electromagnetic radiation such as visible light was considered to behave as a wave: hence the use of the terms "frequency" and "wavelength" to characterise different types of radiation. The energy transferred by a wave in a given time is called its intensity. The light from a theatre spotlight is more intense than the light from a domestic lightbulb; that is to say that the spotlight gives out more energy per unit time and per unit space(and hence consumes more electricity) than the ordinary bulb, even though the colour of the light might be very similar. Other waves, such as sound or the waves crashing against a seafront, also have their own intensity. However, the energy account of the photoelectric effect didn't seem to agree with the wave description of light.

Q1: Before Einstein, electromagnetic radiation was considered to behave as what?
A1: a wave
Q2: What terms describe different types of radiation?
A2: "frequency" and "wavelength"
Q3: What other types of wave besides light has its own intensity?
A3: sound
Q4: What is the energy transferred by a wave in a given time called?
A4: intensity
Q5: Prior to Einstein's work, light behavior was modeled as what?
A5: a wave
Q6: What is the name for the amount of energy transfered by a wave in a given time?
A6: intensity
Q7: What portion of the photoelectric effect was in disagreement with the believed description of light behavior?
A7: the energy account
Q8: What does it mean for a light source to be more intense than another?
A8: gives out more energy per unit time and per unit space
The "photoelectrons" emitted as a result of the photoelectric effect have a certain kinetic energy, which can be measured. This kinetic energy (for each photoelectron) is independent of the intensity of the light, but depends linearly on the frequency; and if the frequency is too low (corresponding to a photon energy that is less than the work function of the material), no photoelectrons are emitted at all, unless a plurality of photons, whose energetic sum is greater than the energy of the photoelectrons, acts virtually simultaneously (multiphoton effect)  Assuming the frequency is high enough to cause the photoelectric effect, a rise in intensity of the light source causes more photoelectrons to be emitted with the same kinetic energy, rather than the same number of photoelectrons to be emitted with higher kinetic energy.

Q1: What is emitted as a result of the photoelectric effect?
A1: photoelectrons
Q2: What does the kinetic energy of a photoelectron depend on?
A2: the frequency
Q3: What happens if the photoelectron's frequency is too low?
A3: no photoelectrons are emitted at all
Q4: What is the term used when photoelectrons act virtually at the same time?
A4: multiphoton effect
Q5: What type of energy due photoelectrons emitted due to the photoelectric effect have?
A5: kinetic
Q6: What factor of the initial light source does the energy of the photoelectrons depend on?
A6: frequency
Q7: When the photon energy is less than the work function of the material the light is shone upon, how many photoelectrons are emitted?
A7: no photoelectrons are emitted at all
Q8: If the photoelectric effect is occuring, increasing the intensity of the light source causes what?
A8: more photoelectrons to be emitted with the same kinetic energy
Niels Bohr introduced the first quantized model of the atom in 1913, in an attempt to overcome a major shortcoming of Rutherford's classical model. In classical electrodynamics, a charge moving in a circle should radiate electromagnetic radiation. If that charge were to be an electron orbiting a nucleus, the radiation would cause it to lose energy and spiral down into the nucleus. Bohr solved this paradox with explicit reference to Planck's work: an electron in a Bohr atom could only have certain defined energies En

Q1: Who introduced the first quantized model of the atom?
A1: Niels Bohr
Q2: When was the first quantized model of the atom introduced?
A2: 1913
Q3: Why was the first quantized model of the atom introduced?
A3: to overcome a major shortcoming of Rutherford's classical model
Q4: In classical electrodynamics, a charge moving in a circle should do what?
A4: radiate electromagnetic radiation
Q5: Who modeled the atom in 1913, challenging Rutherford's model?
A5: Niels Bohr
Q6: What was predicted to happen to a nucleus-orbiting electron under Rutherford's model?
A6: the radiation would cause it to lose energy and spiral down into the nucleus
Q7: What statement did Bohr make about the electron of an atom, citing Planck's work?
A7: an electron in a Bohr atom could only have certain defined energies
Bohr also introduced the quantity , now known as the reduced Planck constant, as the quantum of angular momentum. At first, Bohr thought that this was the angular momentum of each electron in an atom: this proved incorrect and, despite developments by Sommerfeld and others, an accurate description of the electron angular momentum proved beyond the Bohr model. The correct quantization rules for electrons – in which the energy reduces to the Bohr model equation in the case of the hydrogen atom – were given by Heisenberg's matrix mechanics in 1925 and the Schrödinger wave equation in 1926: the reduced Planck constant remains the fundamental quantum of angular momentum. In modern terms, if J is the total angular momentum of a system with rotational invariance, and Jz the angular momentum measured along any given direction, these quantities can only take on the values

Q1: Who introduced the reduced Planck constant?
A1: Bohr
Q2: What is the reduced Planck constant also known as?
A2: the quantity
Q3: Who helped to give the correct quantization rules for electrons in 1925?
A3: Heisenberg
Q4: Who helped to give the correct quantization rules for electrons in 1926?
A4: Schrödinger
Q5: According to Heisenberg and Schrödinger, the reduced Planck constant remains what?
A5: the fundamental quantum of angular momentum
Q6: Bohr introduced what value as the quantum of angular momentum?
A6: the reduced Planck constant
Q7: What incorrect belief did Bohr hold about the reduced Planck constant?
A7: Bohr thought that this was the angular momentum of each electron in an atom
Q8: What scientist used matrix mechanics to bring electron behavior in line with the Bohr model?
A8: Heisenberg
Q9: When was the Schrödinger wave equation proposed?
A9: 1926
where the uncertainty is given as the standard deviation of the measured value from its expected value. There are a number of other such pairs of physically measurable values which obey a similar rule. One example is time vs. energy. The either-or nature of uncertainty forces measurement attempts to choose between trade offs, and given that they are quanta, the trade offs often take the form of either-or (as in Fourier analysis), rather than the compromises and gray areas of time series analysis.

Q1:  What measurable value obeys a similar rule of angular momentum?
A1: time vs. energy
Q2: What forces measurement attempts to choose between trade-offs, in quanta?
A2: either-or nature of uncertainty
Q3: What form do measurement attempt trade-offs for quanta take the form of?
A3: either-or (as in Fourier analysis)
Q4: How is uncertainly measured in this experience?
A4: the standard deviation of the measured value from its expected value
Q5: What type of analysis fits the either-or nature of the uncertainty?
A5: Fourier analysis
Q6: What example is given as another paired relationship of uncertainly related to standard deviation?
A6: time vs. energy