Physics Flashcards: Evaluate Wave And Particle Models

What this deck covers

This deck focuses on Evaluate Wave And Particle Models, giving you a quick way to review the definitions, rules, and examples that matter most for Physics.

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Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: What is the momentum of a photon in terms of energy in the particle model?

Answer: $p=\frac{E}{c}$. Relates photon momentum to energy using $E=pc$ for massless particles.

Flashcard 2: Which change increases photoelectron $K_{\max}$: increasing light intensity or increasing frequency?

Answer: Increasing frequency. Higher $f$ means more energy per photon after work function.

Flashcard 3: Find $K_{\max}$ if $hf=4.0\,\text{eV}$ and $\phi=2.5\,\text{eV}$ in the photoelectric effect.

Answer: $K_{\max}=1.5\,\text{eV}$. Subtracts work function from photon energy: $4.0-2.5=1.5$ eV.

Flashcard 4: Identify the correct model: Light transfers energy in discrete packets and ejects electrons instantly above $f_0$.

Answer: Particle (photon) model. Instant emission and discrete energy packets indicate photons.

Flashcard 5: Which model (wave or particle) directly explains the photoelectric effect?

Answer: Particle (photon) model. Photons transfer discrete energy packets to electrons.

Flashcard 6: What is the speed of electromagnetic waves in vacuum, $c$, in terms of $f$ and $\lambda$?

Answer: $c=f\lambda$. Wave equation relates speed to frequency and wavelength.

Flashcard 7: What is the photon momentum formula in terms of wavelength $\lambda$?

Answer: $p=\frac{h}{\lambda}$. de Broglie relation gives photon momentum from wavelength.

Flashcard 8: Identify the correct statement: intensity changes photon energy or photon number per second?

Answer: Intensity changes photon number per second. Higher intensity means more photons, not higher energy per photon.

Flashcard 9: What is the photon energy formula written using wavelength instead of frequency?

Answer: $E=\frac{hc}{\lambda}$. Substitutes $f=\frac{c}{\lambda}$ into $E=hf$ to express energy in terms of wavelength.

Flashcard 10: What is the photoelectric threshold condition for electron emission in terms of $hf$ and $\phi$?

Answer: Emission if $hf\ge\phi$. Photon energy must exceed work function to eject electrons.

Flashcard 11: Which model (wave or particle) best explains radiation pressure via momentum transfer?

Answer: Particle (photon) model. Photons carry momentum $p=E/c$ that transfers on impact.

Flashcard 12: Which model (wave or particle) best explains discrete atomic emission and absorption lines?

Answer: Particle (photon) model. Photons with specific energies match discrete atomic energy level transitions.

Flashcard 13: Which model (wave or particle) best explains interference and diffraction of light?

Answer: Wave model. Waves can superpose and bend around obstacles, explaining these phenomena.

Flashcard 14: What happens to photon energy when frequency increases, according to $E=hf$?

Answer: Photon energy increases. Direct proportionality: doubling frequency doubles photon energy.

Flashcard 15: What is the photon energy formula relating energy $E$ to frequency $f$?

Answer: $E=hf$. Planck's constant $h$ links photon energy to frequency.

Flashcard 16: What is the momentum of a photon in terms of wavelength in the particle model?

Answer: $p=\frac{h}{\lambda}$. de Broglie relation shows photons have momentum inversely proportional to wavelength.

Flashcard 17: What is the stopping potential relation to maximum kinetic energy in the photoelectric effect?

Answer: $eV_s=K_{\max}$. Stopping voltage times electron charge equals maximum kinetic energy.

Flashcard 18: Find photon energy for $f=5.0\times10^{14}\,\text{Hz}$ using $h=6.63\times10^{-34}\,\text{J·s}$.

Answer: $E=3.3\times10^{-19}\,\text{J}$. Multiplies Planck's constant by frequency: $6.63\times10^{-34}\times^5.0\times10^{14}$.

Flashcard 19: What is the photoelectric threshold condition for emission using work function $\phi$?

Answer: $hf\ge\phi$. Photon energy must exceed work function to eject electrons from metal.

Flashcard 20: What is the threshold frequency $f_0$ in terms of work function $\phi$?

Answer: $f_0=\frac{\phi}{h}$. Minimum frequency where photon energy equals work function.

Flashcard 21: Which model (wave or particle) best explains the photoelectric effect observations?

Answer: Particle (photon) model. Photons explain instant emission and frequency threshold, not wave intensity.

Flashcard 22: What is the work function relation to threshold frequency $f_0$?

Answer: $\phi=hf_0$. Work function equals minimum photon energy for emission.

Flashcard 23: Choose the outcome: If $f<f_0$, what is the photoelectric emission result regardless of intensity?

Answer: No electrons are emitted. Below threshold frequency, photons lack energy to overcome $\phi$.

Flashcard 24: What is the photon energy formula in the particle model of electromagnetic radiation?

Answer: $E=hf$. Planck's equation shows energy is quantized in packets proportional to frequency.

Flashcard 25: Which model (wave or particle) directly explains interference and diffraction of light?

Answer: Wave model. Waves superpose to create interference patterns.

Flashcard 26: Find the photon energy for $f=6.0\times10^{14}\ \text{Hz}$ using $h=6.63\times10^{-34}\ \text{J·s}$.

Answer: $E\approx^4.0\times10^{-19}\ \text{J}$. $E=hf=(6.63\times10^{-34})(6.0\times10^{14})\approx^4.0\times10^{-19}$ J.

Flashcard 27: Which option best supports the photon model: emission occurs with no time delay above $f_0$?

Answer: Particle (photon) model. Instant emission above threshold supports photon model over wave buildup.

Flashcard 28: What is the maximum kinetic energy of photoelectrons in terms of $f$ and $\phi$?

Answer: $K_{\max}=hf-\phi$. Excess photon energy beyond work function becomes electron kinetic energy.

Flashcard 29: Identify the correct model: A double-slit pattern of bright and dark fringes is observed for light.

Answer: Wave model. Interference fringes result from wave superposition.

Flashcard 30: Identify the model best supported by polarization of light (wave or particle).

Answer: Wave model (transverse wave). Only transverse waves can be polarized by filtering.

Flashcard 31: What is the maximum kinetic energy of photoelectrons in the photoelectric effect?

Answer: $K_{\max}=hf-\phi$. Excess photon energy becomes electron kinetic energy.

Flashcard 32: Which change increases the photoelectric current (number of emitted electrons): higher intensity or higher frequency (above $f_0$)?

Answer: Higher intensity. More photons (intensity) means more electrons if $f>f_0$.

Flashcard 33: What is the wave-model relation between wave speed, frequency, and wavelength for EM radiation?

Answer: $c=f\lambda$. Fundamental wave equation relating speed, frequency, and wavelength.

Flashcard 34: Which model (wave or particle) explains Compton scattering as a wavelength increase after scattering?

Answer: Particle (photon) model. Photon-electron collision transfers momentum and energy.

Flashcard 35: Choose the correct model for Compton scattering (X-ray wavelength increases after scattering).

Answer: Particle (photon) model. X-ray photons transfer momentum to electrons, losing energy and increasing $\lambda$.

Flashcard 36: Find $\lambda$ for $f=6.0\times10^{14}\,\text{Hz}$ using $c=3.0\times10^8\,\text{m/s}$.

Answer: $\lambda=5.0\times10^{-7}\,\text{m}$. Uses $\lambda=\frac{c}{f}=\frac{3.0\times10^8}{6.0\times10^{14}}$.

Flashcard 37: What happens to wavelength when frequency increases, using $c=f\lambda$?

Answer: Wavelength decreases. Since $c$ is constant, $f$ and $\lambda$ are inversely proportional.

Flashcard 38: Find the photon wavelength for $f=5.0\times10^{14}\ \text{Hz}$ using $c=3.0\times10^8\ \text{m/s}$.

Answer: $\lambda=6.0\times10^{-7}\ \text{m}$. $\lambda=c/f=(3.0\times10^8)/(5.0\times10^{14})=6.0\times10^{-7}$ m.