Which type of bond forms between atoms of iron (Fe)? A. ionic
B. Metallic
C. Polar covalent
D. Nonpolar covalent

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; carbon monoxide (co);