Representation of an object or event

3. how much energy in joules is required to evaporate .0005 kg of liquid ammonia to vapor at the same temperature? 4. how much energy ( in megajoules ) is given up by .75 kg of water at 0c when it freezes to form ice at 0c? 5. explain how heat works between and at critical temperatures?

Which of the following is a physical change? a.burning a piece of wood b.sawing a piece of wood in half c.rust forming on an iron fence d.a copper roof changing color from orange to green

Spaghetti sauce can be high in sodium. what is a good guideline for mg of sodium per half cup serving? a. less than 1 mg b. less than 800 mg c. less than 700 mg d. less than 400 mg