1º_ It is the consonant "hache" in the Latin alphabet. For Spanish it has no sound of its own, although it alters that of the /c/ in the digraph /ch/ and in foreign words it can do the same with /sh/ and even have a pronunciation similar to the aspirated /j/ . 2º_ 'H' is the chemical symbol of hydrogen, also of the amino acid histidine; In physics it is the symbol for the henry (for electrical inductance) and the strength of a magnetic field; in musical notation by letters H is used as a way to differentiate the note si from its altered version B molle (B flat) which is currently only maintained in Germany. 3º_ 'h' is a symbol for "time" (see m, s); also for the prefix hecto ("one hundred").
