The isoelectric point (pI) of an amino acid isthe pH at which the net charge of thatmolecule equals zero, i. e., the + and – charges arebalanced). Calculate the pI for
histidine (draw all 4 of the ionic forms starting with thefully protonated species. Identify the pKa values of each ionization and find the specieswith no net charge)

in 1783 cavendish was working with his hydrogen gas and found that when he burned it and condensed the vapor it was water. this was very significant since it disproved the greek theory of elements completely since water was not a simple substance but the product of two gases. it was lavoisier who hearing of the experiment gave cavendish's gas the name hydrogen ("water-producer") and added that hydrogen burned by combining with oxygen and that water was a hydrogen-oxygen combination.

explanation:

a is the correct answer