When zinc metal is mixed with hydrochloric acid, vigorous production of what substance is an indication that a chemical
reaction is occurring?

The answer is nitrogen-containing bases

Hello thereone of the following properties was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version. which property fits this description? answer: atomic mass  was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.