Subject: Why are the concepts of universal law of gravity and coulombs law different

I understand that both laws look the same and mathematically function the same. 
But here is where the difference arises. Bigger planets have a higher force of 
attraction compared to smaller planets, and that's according to Newton's 
universal law of gravitation where force of attraction is proportional to mass 
of each object. However, in chemistry, the bigger the atom (or bigger ionic 
radii), the less attractive force it has with it's bonded partner. Why not the 
bigger the atom, the higher the force of attraction? That's where my confusion 
is.
Lastly, if the size of Earth increases, does that mean the force of gravity 
acting on me would increase? If so, why?

Re: Why are the concepts of universal law of gravity and coulombs law different