At STP, a powered 4.0-gram zinc sample would react fastest dilute hydrochloric acid.
It's B, because a negative charged Ion is an anion. And since it's 1- ,one valence electron is been added to H. So it has 2 valence electrons.
Answer is: Louis Pasteur (1822-1895) disproved spontaneous generation. He boiled liquid with proteins and other nutrients in S-neck flasks and regular flask to kill all microorganism present. In regular flask liquid showed changes when exposed to air and in S-neck flack there was no change (microorganism can not getting in the flask because the S- neck). When he removed S-neck, liquid changed because microorganisms came in liquid.
Pasteur showed it was not the air itself but particles within the air that had microorganisms.
The answer is B. Chemical change
