Wave generated with particle excitement To my understanding, an electromagnetic wave(infact two perpendicular fields) will be emitted when a particle(e-) shifts from higher energy orbital to lower energy  orbital but what would be the distance that it can travel and when does the energy in it deteriorates ?
For this matter how can EM waves travel so longer distances ?
 A: As you stated right, any electromagnetic radiation is based on the emission of photons from excited particles like electrons and protons. The emitted photons are indivisible units and every photon has an electric field component and a magnetic dipole component. This fields transform themselves into one another (like in a resonant circuit) and traveling through vacuum with a constant speed (the velocity of light).
Sources of electromagnetic radiation could be for example a thermal source like a bulb, an antenna or a laser.
The EM radiation from a thermal source has not the properties of a wave. Nor any amplitude nor any frequency is detectable. The oscillating photons of such EM radiation are emitted randomly and this photons have a wide range of frequencies.
The EM radiation from an antenna has the properties of a wave. The modulation of such an EM radiation is produced with an antenna generator which accelerates electrons on an antenna rod backwards and forwards. It is important to recapitulate that the emitted photons in such a radio wave have wavelengths from infrared to gamma rays.
All EM radiation could travel infinite but since not one EM radiation could be focused on a point (truth for lasers too) the density of the radiation could be so weak that a detector will detect only single photons.
