What is the energy and momentum of a photon having frequency $v$?

$A$ photon and an electron, each of $20 \text{ eV}$ energy, move in free space. The ratio of linear momentum of electron $p_e$ to that of photon $p_{ph}$ is : (Take speed of light = $3 \times 10^8 \text{ ms}^{-1}$, charge of electron = $-1.6 \times 10^{-19} \text{ C}$ and mass of electron = $9 \times 10^{-31} \text{ kg}$)

If $n_r$ and $n_b$ are the number of photons emitted per second by a red bulb and a blue bulb of equal power respectively,then:

$10^{20}$ photons of wavelength $660 \ nm$ are emitted per second from a lamp. The wattage of the lamp is (Planck's constant $h = 6.6 \times 10^{-34} \ J \cdot s$). (in $W$)

The fact that photons carry energy was established by

The value of Planck's constant is