QCAA Physics Alternative Sequence Quantum theory

A positively ionised metal would exert a stronger attractive force on the electrons, effectively increasing the energy required to remove them and decreasing their maximum kinetic energy.

According to the photoelectric equation $K_{\text{max}} = hf - \Phi$, using a metal with a larger work function ($\Phi$) would decrease the maximum kinetic energy of the ejected electrons.

Increasing the intensity of the incident light increases the number of ejected electrons per second, but it does not change the energy of individual photons or the maximum kinetic energy of the electrons.

This incorrect value is obtained by multiplying the energy by the speed of light ($E \cdot c$), rather than using the correct wave energy formula.

This incorrect value is obtained by dividing Planck's constant by the energy ($h/E$), which calculates the inverse of the frequency, not the wavelength.

This incorrect value is the inverse of the wavelength ($1/\lambda$), obtained by calculating $\frac{E}{hc}$ instead of $\frac{hc}{E}$.

An X-ray is a specific type of high-energy electromagnetic radiation, not the general term for a discrete packet or quantum of radiation.

A positron is the antimatter counterpart to an electron, having mass and a positive charge, whereas a quantum of electromagnetic radiation is a massless particle.

An electron is a fundamental subatomic particle with mass and a negative charge, not a massless quantum of electromagnetic energy.

Incorrect. This result is off by a factor of 10, which would occur if the velocity was $1 \text{ m s}^{-1}$ instead of $10 \text{ m s}^{-1}$.

Incorrect. This answer is off by a factor of 100, likely due to a miscalculation of the momentum denominator $mv = 6630 \text{ kg m s}^{-1}$.

Incorrect. This is approximately the value of Planck's constant ($6.63 \times 10^{-34} \text{ J s}$), which means the momentum $mv$ was incorrectly treated as $1 \text{ kg m s}^{-1}$.

While slit width affects the intensity and diffraction envelope of the pattern, the actual phenomenon of interference is fundamentally caused by wave superposition, not the physical dimensions of the slits.

Describing light as discrete packets of photons refers to its particle nature, which explains phenomena like the photoelectric effect rather than classical wave interference.

The distance to the screen affects the spacing between the interference fringes (given by $y = \frac{\lambda L}{d}$), but it does not explain the fundamental physical cause of the interference pattern itself.

White light passing through a prism demonstrates dispersion and refraction, which are phenomena explained by the wave nature of light and its varying wavelengths.

Diffraction is the bending of light as it passes through a slit, which is a classic characteristic of waves rather than particles.

Interference patterns are created by the superposition of overlapping waves, providing foundational evidence for the wave model of light.

Incorrect. The energy supplied by the incident photon is represented by the term $hf$, not $\phi$.

Incorrect. The energy retained by the electron as kinetic energy after being ejected is represented by $K_{\text{max}}$.

Incorrect. The energy left over after freeing the electron becomes its maximum kinetic energy, represented by $K_{\text{max}}$.

Incorrect. This describes John Dalton's early atomic theory. Rutherford's model focused on the internal structure of the atom rather than its indivisibility.

Incorrect. This describes J.J. Thomson's plum pudding model. Rutherford's work specifically disproved this model by showing the positive charge is concentrated in a central nucleus.

Incorrect. This describes the Bohr model. Rutherford proposed orbiting electrons, but it was Niels Bohr who introduced the concept of quantized orbits with fixed energy levels.

This is the threshold frequency, calculated using only the work function ($\Phi/h$), which ignores the additional energy needed for the kinetic energy of the ejected electron.

This frequency incorrectly corresponds to the difference between the kinetic energy and the work function, rather than their sum.

This frequency corresponds only to the kinetic energy of the electron ($K/h$), ignoring the energy required to overcome the metal's work function.