Which solution is an example of an electrolyte

Evaluate this exponential expression,8. (2 + 3)2 – 42

Which substances have the lowest melting points: ionic covalent, or metallic

Consider the following reactions. (note: (s) = solid, (l) = liquid, and (g) = gas.) mg(s) + ½o2(g) → mgo(s) + 146 kcal/mole h2(g) + ½o2(g) → h2o(g), δh = -57.82 kcal/mole what type of reaction is represented by the previous two examples?