When you boil water, you aren't changing the elements. You're just making water vapor. However, when you burn paper, it becomes carbon (mostly). So physical changes will not change the substance, only chemical changes will.
At the constant temperatures the lighter the gas molecules, the faster the average velocity of the gas molecules.
Answer:
second law of thermodynamics.
Explanation:
The second law of thermodynamics deals with interconversion of energy from one form to another. Although energy can be converted from one form to another, this conversion is never 100% efficient because energy is lost in certain ways such as through heat. In a combustion engine, it is not possible to recover the energy from the gasoline 100% since energy must be lost along the way via such means as heat losses. Hence I will be skeptical about such an advert.
