I need to write the definition with an example what it means. the word is opaque

Sound does not need a medium to travel is reflected when it bounces off a shiny surface is created by electric and magnetic fields moves in longitudinal waves

What is the thermodynamic driving force for dissolving a solid in a liquid if it is an endothermic process (which reduces the entropy of the surroundings)? 1. the combustion of propane. 2. the increase of the entropy of the system. 3. increased temperature of the system and surroundings. 4. the decrease of the entropy of the system. 5. the increase or decrease of the entropy of the system?

An someone plz me with questions 1 and 2 plz