Answer:
Osmium
Explanation:
The metals conduct electricity the best, in this question the metal would be osmium.
A. soluble.
The are solubility rules that predict precipitation reaction.
freezing-energy lost (exothermic)
sublimation-energy gain (endothermic)
evaporation- energy gain(endothermic)
Melting- energy gain(endothermic)
deposition- energy lost(exothermic)
condensation-energy lost(exothermic)
Please refer to the attachment for a complete classification of your specified matter.