A radiation emitted from a hot iron is photon or quantum ?

Electron of energies 10.20 eV and 12.09 eV can cause radiation to be emitted from hydrogen atoms . Calculate in each case, the principal quantum number of the orbit to which electron in the hydrogen atom is raised and the wavelength of the radiation emitted if it drops back to the ground state.

The value of wavelength radiation emitted by an H -atom, if atom is excited to state with principal quantum number four is :

The rate of radiation of energy from a hot object is maximum, if its surface is

According to Planck's quantum theory of light, every source of radiation emits photons (i.e., packets of energy ) which travel in all directions with the same speed (i.e., speed of light). Each photon is of energy E=hv=hc//lambda , where h is Planck's constant, v is the frequency and lambda is wavelength of radiation emitted. The photons emitted from different sources of radiation are different. Read the above passage and answer the following questions: (i) on what factors does the number of photons emitted per second from a source of radiations depends? (ii) Why are the high energy photons not vissible to eye? (iii) Which basic values do you learn from this study?