S. Which statement best describes what happens to the particles of matter during this change?

In atoms, the electron carries a negative elementary or unit charge; the proton carries a positive charge. the two types of charge are equal and opposite. in an atom of matter, an electrical charge occurs whenever the number of protons in the nucleus differs from the number of electrons surrounding that nucleus.

A=v^2/r solve for r hope that  

The answer is "iron"