harry95' said:
Im trying to wrap my head around this. If a photon of the right energy hits an atom's electron (hydrogen e.g) it jumps to the next orbital shell, then goes back down to conserve energy releasing a photon in the process. is this how we see the atoms in everyday matter? by the switching of the electrons state from excited to ground? And if so do the electrons have to constantly change in order for the object to give of its light? this is really confusing me
We do not see stuff by the same process that hydrogen gas can glow. You can tell this because stuff does not normally glow.
Hydrogen is used as a starting point to teaching about atomic transitions in terms of individual electron orbitals - it's an old model and simplistic. Do not expect it to tell you everything about light. But it is still a decent place to start - so I'll start there to see if I can give you a glimpse at a more complete idea: I'll start with what you already know about hydrogen, in simple terms (@everyone else: I know - let the simple stuff sink in first OK?!) and extend to more complicated situations - also in simple terms.
So looking at hydrogen: the process you described only happens when the photon has the right energy (the difference between the shells) and there is usually something else to cause the de-excitation. Details depend on the exact two shells.
An electron may be promoted to quite a high energy - though these are usually better thought of as atomic energy states rather than electron states - in which case, it may find itself headed back to the ground state in a series of transitions rather than going all in one go. It releases a photon at each transition - so a single photon in can, in principle, get a series of photons out. Some of the photons out may be in the visible spectrum - which gives the gas the color that it glows at, we can see it when it is hot or if we manipulate it via an applied electric field. When it does not glow in the visible spectrum, we don't usually think of it as having a color.
An atom does not have to lose energy by radiating; it can also lose energy in "collisions" with other atoms, it may share energy with other atoms in the same molecule, the molecule itself may collide with other molecules stuff like that. The denser the matter, the bigger the molecule or crystal or what-have-you, the more ways the bulk object may deal with the energy on an atom-by-atom basis ... this is why the short answer to your question is "no".
You also asked about color:
A bulk object gets it's color primarily by absorbing a band of wavelengths in the visible spectrum. This should have been taught at secondary level but it usually needs to be repeated.
It can do this because the structure of the object at the atomic and molecular levels allows the energy involved with those wavelengths to be favorably removed by other processes - just like the orbital structure of atoms allows it to absorb some wavelengths and not others. Usually a lot of the absorbed energy ends up as random motion of atoms - heat. It gets diffuses through the object by "collisions" - atoms pushing and pulling on their atomic bonds, that sort of thing. When the object warms up, then the energy may also get re-radiated ... at room-temperature this is usually infrared so you don't see it so it does not contribute to the object's color. Heat it up a lot and it may radiate in the visible spectrum - hot objects do glow.
The bottom line is: it's not that simple. The single process isolated in the hydrogen experiments you've probably seen is not the only thing that is going on. What we experience as out everyday life is a combination of many different processes - even with something as apparently straight forward as light scattering from a surface.
