What is true about energy?

energy cannot be created during an ordinary chemical reaction.

energy is used up during an explosion.

there is more energy after a chemical reaction than before the reaction.

when water melts, energy is created in the form of heat.

Nitric oxide (no) can be formed from nitrogen, hydrogen and oxygen in two steps. in the first step, nitrogen and hydrogen react to form ammonia: n2(g) + 2 h_2(g) rightarrow 2 nh_3 (g) delta h = -92. kj in the second step, ammonia and oxygen react to form nitric oxide and water: 4 nh_3(g) + 5 o_2(g) rightarrow 4no(g) + 6 h_2o(g) delta h = -905. kj calculate the net change in enthalpy for the formation of one mole of nitric oxide from nitrogen, hydrogen and oxygen from these reactions. round your answer to the nearest .

Jessica is traveling from miami, florida, to chicago, illinois. using the map, tell one way the land will change during the second half of her trip.

The best solution for preventing harm to people and pets from severe hurricanes involves determining and warning residents about what