How many milliliter did 2.5M HCL are required to exactly neutralize 15 milliliters of 5.0M NaOH

Is this a single replacement reaction or there is no

With the largest atoms and the smallest number of valence electrons and with the smallest atoms and the greatest number of valence electrons are the most reactive. a. nonmetals; metals b. nonmetals; transition elements c. transition elements; metals d. metals; nonmetals

What physical property of gold makes panning a useful way to get gold from streams?