Step1 NaF is the correct answer Step2 Na+ + e ----> Na ; 2 Na(s) + 2H2O(l)--- >2NaOH(aq)+ H2(g) Step3 2F- -----> F2(g) +2e Step4 2F2 (g) +2 H2O(l)------> 4HF(aq )+ O2 (g) Solution Step1 NaF is the correct answer Step2 Na+ + e ----> Na ; 2 Na(s) + 2H2O(l)--- >2NaOH(aq)+ H2(g) Step3 2F- -----> F2(g) +2e Step4 2F2 (g) +2 H2O(l)------> 4HF(aq )+ O2 (g).