Manual says that he has reduce the amount of thermal energy in a cup of hot chocolate without lowering the temperature. How is that possible?

If we compare and contrast electromagnetic waves with sound waves, all but one statement is true. that is a) sound waves require a medium to travel while electromagnetic waves do not. b) electromagnetic waves can travel through the vacuum of space while sound waves cannot. c) electromagnetic waves must have a medium in which to travel, but sound waves can travel anywhere. eliminate d) sound waves must bounce off of matter in order to travel while electromagnetic waves do not require matter to be present.

Compare and contrast refraction of light and sound will give brainliest

What substance has a mass of 9.5g and volume of 2.1cm^3