The hammering on a train track is often heard twice by workers farther down the track; first as the sound travels through the steel and second as the sound travels through the air. this suggests which graph is true?

Sorry i dont understand the question can you rephase it?

Answerδh > 0explanationc₆h₆  (s)  → c₆h₆ (l)if you are changing it from a solid to a liquid, you are pretty much melting the solid. this requires heat energy. therefore, the reaction is endothermic (takes in energy); the system enthalpy increases as the reaction proceeds: δh > 0.

Answer(2) electrons;