Its made up of a long chain of monomers so proteins are polymers made of amino acids I hope this helps! ^^;
Sodium will have a larger radius. Look up the atomic radius Trend
Chlorine is more reactive than argon, because argon is not reactive at all. Chlorine only has to gain 1 valence electron
Formula for calculation of neutrons is Mass number - atomic number, here values are given. By putting values in formula 76-35= 41. Number of neutrons 41
