Why ionization energy is defined as the energy required to remove the outermost, or highest energy, electron from a neutral atom in the gas phase. Why can't we remove electrons from a solid,can we? If not ,what's the reason?I think we can not remove electrons from a solid because in gas phase molecules or gaseous atoms are far apart so in order to remove electron we just have to overcome attraction of nucleus of that particular atom from which we are removing electrons.But in solid state ,there is attraction between adjacent atoms ,so to remove electrons we have to overcome attraction of several atoms .Am I right? Sorry if my reasoning is just not making any sense.But in order to correct myself I will have to show my thinking, my views.Doesn't matter right or wrong. Thanks.