**PLEASE SHOW YOUR WORK**Calculate how much energy would be necessary to convert 250.0 grams of ice at -30°C to steam at 145°C. Assume that the only time that liquid water changes to gas is when it is boiling. Please help me

Ok, so i have 2 questions. try to answer them both: (the topic is fire) 1) how can you represent the chemical reaction of fire? 2) what kind of bond is formed in this chemical reaction

The most common form of matter in the universe

4al + 3o2 → 2al2o3 what does the "3" in front of o2 stand for? a) it indicates that there are 5 oxygen atoms after you add the coefficient and the subscript. b) it indicates that that there are are total of 6 oxygen atoms all bonded together as a single molecule. c) it indicates that there are 3 oxygen molecules chemically bonded to each other in the reaction. d) it indicates that there are 3 separate oxygen molecules in the reaction.