A floodlight consumes 15.3 kJ of energy. It is found that it delivers only 3.9 kJ of useful light. What is the % efficiency of this floodlight?

the increase of protons   hope this

water and alcohols have similar properties because water molecules contain hydroxyl groups that can form hydrogen bonds with other water molecules and with alcohol molecules, and likewise alcohol molecules can form hydrogen bonds with other alcohol molecules as well as with water.