Really need the help. Potassium reacts with a certain nonmetallic element to form a compound with
the general formula K2X. Element X must be from which group on the periodic
table? Explain, using complete sentences, how you know this.

Outermost (valence) electrons

Okay well gravitational energy is matter forced by gravity making energy though the kinetic energy then the electric energy produces electricity from the kinetic energy and the kinetic energy gets its energy from the gravitational energy. was that the answer you wanted or something else?  

Answer two atoms of oxygen;