Rank the physical and chemical changes in order of decreasing of the amount of energy released: (a) the condensation of rain in a thunderstorm, (b) the burning of a gallon of gasoline in a car engine, (c) the explosion of a firecracker.

What three natural resources are found in the great lakes region

Mary is conducting an experiment on how pollution affects plant growth. how can she ensure that her data are reliable?

Which statement about hf is true? it is zero for any compound in its standard state. it is positive when the bonds of the product store more energy than those of the reactants. it is negative when a compound forms from elements in their standard states. it is zero for any element that is in the liquid state.