Rank from most to least metallic character. To rank items as equivalent, overlap them. P, F , Co, Rb, Cr, S, ZN, Ca

Rn in the right answer

3-isopentane; 3-methylbutane, and 1,2-methylpropane do not meet iupac rules, so they are wrong names.the only valid name onthe list is 2-methylbutane, which is the same isopentane.this is its formula:                   ch2                    |ch3 - ch - ch2 - ch3answer: 2-methylbutane