Answer:
See explanation
Explanation:
Electron affinity is the energy released when an extra electron is added to a neutral gaseous atom. A negative value of electron affinity indicates that energy is given out and vice versa.
Metals have positive electron affinity since electrons rarely accept electrons, so;
Na(g)+ 1e^- → Na^-(g) positive
Mg(g)+1e^- → Mg^-(g) positive
For the last case; Br(g)+ 1e^- → Br^-(g), the electron affinity for the non-metals is negative. hence the answer
Answer:
Catod: K^(+), H2O
2H2O + 2e^(-) ---> H2 + 2OH^(-) reduction reaction
Anod: I^(-), H2O
2I^(-) ---> I2 + 2e^(-) oxidation reduction
2H2O + 2I^(-) ---> I2 + H2 +2OH^(-) ionic net reaction
Earth, Air, Water, and Fire
D. all of the above are evidence of a chemical reaction