system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: why does adding a proton completely change the properties of one element to another.

It it only because of the extra electrons? Do the protons actually do something?  Does adding neutrons add any properties other than then possibility of a decaying isotope?  I don't get how for example a proton changes carbon to nitrogen and all the properties than includes (solid to gas, black to colorless)
gpt
Two atoms will find their most stable positions relative to each other by how the cloud of electrons around them interact and this makes up most of their interaction under the conditions we find here on Earth. The number of protons affects the behavior of the electron clouds with more protons attracting more electrons.

All of the properties you discuss, such as the properties of their phase changes or coloration, are electrical in nature and largely come from the interaction of these electron clouds. For example, the color of a substance is a result of which wavelengths of light the electrons of a material will absorb, which is in turn a result of the density of the electron cloud around the nucleus, which is in large part a result of the charge of the nucleus which is dependent on the number of protons present.