The number to the right of an element's symbol (ex. c-12) identifies the of an isotope.

Ithink that one is (c)

Answerethyl pentanoate

The chemical equation is ca(oh)2(s) + h2so4(aq) --> + h2o(l) in low concentrations it will stay in elucidation. at higher concentrations it will be precipitous.the oh- on the left responds with the h+ on the left to make hoh (h2o) as a produce. there's no oh- on the right hand side. so it should look like this:   ca2+ + 2oh- + 2h+ + so4^2- > caso4(s) + 2h2o(l)  hope this ! and mark me as brainliest if you dont mind : )