What is the packet of energy called?

According to Bohr's model,the energy of an electron is given by $E = -\frac{2.176 \times 10^{-18}}{n^2} \, J \, atom^{-1}$. Calculate the minimum energy required to remove an electron from the $3^{rd}$ orbit of a $He^{+}$ ion,and also calculate the corresponding wavelength of the photon.

The angular momentum of an electron in a given orbit is $J$. Its kinetic energy will be:

The electron in a hydrogen atom is in the first Bohr orbit $(n=1)$. The ratio of transition energies,$E(n=1 \rightarrow n=3)$ to $E(n=1 \rightarrow n=2)$,is

Which of the following activities can be compared to the concept of quantisation?

The value of Planck's constant is $6.63 \times 10^{-34} \, J \cdot s$ and the speed of light is $3.0 \times 10^8 \, m \cdot s^{-1}$. The wavelength of a quantum of light with a frequency of $8 \times 10^{15} \, s^{-1}$ is closest to which of the following values in meters?