How do we know that caramelizing sugar is a chemical change? A. It involves dissolving sugar in water. B. It changes the state of sugar from a solid to a liquid. C. It separates sugar from a sugar solution. D. It changes the sugar's color.

The amount of heat required to change liquid water to vapor at its boiling temperature is 2256 kj/kg. the amount of heat required to change liquid mercury to its vapor state at its boiling temperature is 295 kj/kg. one kg of each substance is currently at its boiling point. how will the amount of thermal energy required to change each substance from a liquid to a gas differ?