The microwave region of the electromagnetic spectrum is considered to have wavelengths ranging from $5 \mathrm{mm}$ to $50 \mathrm{cm}$. Calculate the range of energy of microwave photons.

In a microwave oven, the photons are used to warm food. Each photon has energy $1.02\times {10}^{-5}\mathrm{eV}$. Calculate the energy of each photon in joule (J).

In a microwave oven, the photons are used to warm food. Each photon has energy $1.02\times {10}^{-5}\mathrm{eV}$. Calculate the frequency of the photons.

In a microwave oven, the photons are used to warm food. Each photon has energy $1.02\times {10}^{-5}\mathrm{eV}$.

(c) Calculate the wavelength of the photons.

Electrons in an cathode-ray tube are accelerated through a potential difference of $10\mathrm{kV}$. Calculate their energy in electronvolts.

(b) Electrons in an cathode-ray tube are accelerated through a potential difference of $10\mathrm{kV}$. Calculate their energy:

(ii) in joules.

A helium nucleus (charge $=+3.2\times {10}^{-19}\mathrm{C};$ mass $=6.8\times {10}^{-27} \mathrm{kg}$ ) is accelerated through a potential difference of $7500 \mathrm{V}$. Calculate its kinetic energy in electronvolts.