system
Given the following post, respond as if you're commenting on Reddit:
human
Why does adding or removing an electron from an atom completely alter its fundamental properties?

I understand why alkali metals are highly reactive, I understand why Noble gases just chill and I have a basic understanding of why some elements are radioactive or have magnetic properties but let me take Gold (please!):

It's a solid, very dense but the most malleable of the metals, has a melting point of 1064 degrees, a latticed crystal structure and is yellow.   Now if we remove an electron, it becomes platinum, an even denser white silver element with a melting point 700 degrees higher and a cubic crystal structure.  If we add an electron it becomes Mercury with a super low melting point of -39 degrees and a rhombohedral structure.  Add a few more and it becomes poisonous (lead), then turns into a metalloid (Polonium) and then a non-metal (Astatine) all with completely different fundamental properties.

So what's the story here?

Edit: I'm an idiot; the atomic number is of course the proton number.  Don't know what I was thinking.  Still, the question remains.
gpt
>Now if we remove an electron, it becomes platinum

no, it does not. it becomes Au^+1 (gold atom with a charge on it). if you removed a *proton* it would become platinum. and even then, it would be an isotope of platinum, you would have to remove another neutron and electron to get a normal platinum atom.