During photosynthesis,
is used to break water down into oxygen and hydrogen.
oxygen
glucose
sunlight
carbon dioxide

Which of the following signs of a chemical reaction are observed in the reaction of potassium with water? precipitate formed temperature change smell produced gas produced color change

Significant figures are digits read directly from the measuring instrument plus one more digit, which is __ by the observer.

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?