QCAA Physics Quantum Theory

Using a positively ionised metal would increase the electrostatic attraction on the electrons, effectively increasing the energy required to escape and decreasing the kinetic energy.

According to the photoelectric equation $K_{max} = h\nu - \Phi$, increasing the work function ($\Phi$) reduces the remaining energy available for kinetic energy.

Increasing intensity increases the number of photons and ejected electrons (photocurrent), but does not change the energy of individual photons or the maximum kinetic energy of the electrons.

Photon energy is inversely proportional to wavelength ($E = \frac{hc}{\lambda}$). Decreasing the wavelength increases the incident photon energy, thereby increasing the maximum kinetic energy of the ejected electrons.

Interference is a fundamental property of waves where overlapping wavefronts add constructively or destructively; this experiment is the classic evidence for the wave nature of light.

While slit width affects the diffraction envelope and contrast, the interference pattern itself is caused by wave superposition, which can occur even if the slits are not perfectly equal in width.

Discrete packets (photons) refer to the particle nature of light; if light behaved strictly as classical particles, it would form two distinct bands rather than an interference pattern.

The distance to the screen affects the spacing of the fringes (scale), but it is not the fundamental cause of the interference phenomenon itself.