Is everyone in your class able to hear a quiet sound equally well?

If 21.2 kcals of energy is released by this reaction, how many kj does the reaction release? (1 cal 4.184 j)

This is important 1. what happens to the speed of molecules in water vapor when it condenses to form a liquid? (2 points) the molecules slow down. the molecules speed up. the molecules slow down and then speed up. the molecules speed up and then slow down. 2. how might human activities change to compensate for a decrease in water supplies? (2 points) humans might build a factory. humans might build drainage systems. humans might extract more water from the ground. human behavior does not change because of the water cycle. i'll be grateful if anyone can answer these 2 questions !

This is for my 8th grade science class, i really don’t understand. can someone me? , lol.