Why are fewer action potentials recorded at recording electrodes R2 when TTX is applied between R1 and R2? How well did the results compare with your prediction?

Ch4 and ph3 are both covalent since they are composed both of non-metals.    ch4 is non- polar because of  london forces and has a geometry of tetrahedral  ph3 , on the other hand, is umbrella shaped polar and has dipole-dipole intermolecular force (imf) . since ph3 is polar, it has a stronger imf   

Ithink the answer is d.

Answerlimiting reactant;