When the following reaction goes in the reverse direction (from products to reactants), what is the base?
HF(aq) + H2O(l) = F-(aq) + H3O+(aq)

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