15.1 Quantum Physics

• Quantum physics studies the behavior of matter and energy on the atomic and subatomic scale
• Classical physics can adequately explain phenomena at the quantum level.

  False
• Who proposed the concept of quantization in 1900?

  Max Planck
• Planck's quantum theory states that the energy of an oscillating atom can take on any arbitrary value.

  False
• Planck discovered that energy is emitted or absorbed in discrete packets called quanta
• Order the following key concepts of Planck's quantum theory:

  1️⃣ Energy is not continuous

  2️⃣ Energy is emitted in quanta

  3️⃣ Energy values are discrete

  4️⃣ Explained blackbody radiation
• Classical physics assumes continuous energy changes, while quantum physics assumes discrete energy changes.


  True
• Planck's quantization discovery showed that energy is emitted or absorbed in indivisible packets called quanta.


  True
• Steps in Einstein's quantum explanation of the photoelectric effect:

  1️⃣ Light consists of photons with energy E = hf

  2️⃣ Electrons need a minimum energy (work function) to escape

  3️⃣ Electrons are emitted if hf > Φ

  4️⃣ Kinetic energy of emitted electrons is KE = hf - Φ
• What is the formula for the kinetic energy of emitted electrons in the photoelectric effect?

  KE = hf - \Phi</latex>
• What is the key difference between classical and quantum physics views on light scattering?

  Wavelength shift in quantum physics
• Quantum physics describes the world in terms of probabilities, while classical physics describes it in terms of certainties.

  True
• Arrange the historical milestones in the development of quantum physics:

  1️⃣ Max Planck proposes quantization of energy

  2️⃣ Einstein explains the photoelectric effect

  3️⃣ Compton effect provides evidence for particle nature of light
• Match the concepts with their related fields:

  Continuous energy changes ↔️ Classical physics

  Discrete energy values ↔️ Quantum physics
• What does Planck's quantum theory state about the energy of an oscillating atom or molecule?

  Discrete values only
• In classical physics, electron emission in the photoelectric effect depends on light intensity.


  True
• In the photoelectric effect, the minimum energy required for an electron to escape a metal surface is called the work function
• Steps in Einstein's quantum explanation of the photoelectric effect:

  1️⃣ Light consists of photons

  2️⃣ Each photon has energy \(E = hf\)

  3️⃣ Electrons need minimum energy to escape

  4️⃣ Electrons are emitted if \(hf > \Phi\)

  5️⃣ Kinetic energy of emitted electrons is \(KE = hf - \Phi\)
• The Compton shift depends on the scattering angle $\theta$.


  True
• What happens to the photon's energy in the Compton effect?

  It decreases
• Unlike classical physics, the quantum physics view of light scattering explains that light is composed of photons
• Match the light scattering effect with its key characteristic:

  Compton effect ↔️ Photon's wavelength shifts

  Rayleigh scattering ↔️ No wavelength shift

  Mie scattering ↔️ Scattering by larger particles
• In classical physics, light scattering results in a change in wavelength.

  False
• The Compton shift occurs because a photon loses energy during scattering.

  True
• Match the variables in the Compton shift formula with their meanings:

  \(\Delta \lambda\) ↔️ Compton shift

  \(\lambda'\) ↔️ Scattered photon wavelength

  h ↔️ Planck's constant

  m_e ↔️ Electron mass
• What is De Broglie's hypothesis?

  All matter exhibits wave-like behavior
• Match the variables in the De Broglie wavelength formula with their meanings:

  h ↔️ Planck's constant

  p ↔️ Momentum of particle

  m ↔️ Mass of particle

  v ↔️ Velocity of particle
• Electron diffraction experiments confirm De Broglie's hypothesis.


  True
• Classical physics allows for unlimited precision in measuring both position and momentum simultaneously.


  True
• Unlike classical physics, quantum physics follows probabilistic laws of quantum mechanics.
• Quantum physics emerged as a response to the limitations of classical physics.
• Quantum physics deals with large-scale objects.

  False
• What type of laws does quantum physics follow?

  Probabilistic laws
• Quantum physics describes the world in terms of certainties.

  False
• Who proposed the concept of quantization in 1900?

  Max Planck
• Planck discovered that energy is emitted or absorbed in discrete packets called quanta.
• Planck's quantum theory explains the phenomenon of blackbody radiation.
• Quantum physics describes energy as occurring in indivisible quanta.
• What does the photoelectric effect refer to?

  Emission of electrons
• Einstein's quantum explanation states that light consists of photons.

  True