i asked my tenth grade teacher this question but he kept chaning the subject! I am not really familiar with the 'intense' math (im still in my thrid year of undergrad physics) that goes into solid state physics (if this is a question relating to that field of study) so if possible try and explain in layman's terms. anyway... what gives atoms their properties? For example why would something like Mercury have such a low melting point but something adjacent to it on the periodic table have a considerably higher melting point? I do know that trends seem to be carried in the columns of the periodic table... but why would something with +/- 1 atomic number have starkly (once again, i m not sure if that is the case) different properties? I mena its only ONE electron and one proton? How could One electron change the structure of some metal for example?