24 kcal Hawk
carnivore)
470 kcal
Bluejays (omnivore)
4,000 kcal Caterpillars (herbivore)
25,500 kcal
Oak tree leaves (producer)
Sunlight hitting Earth's surface = 3.190,000 kcal.
Label the pyramid levels in Model 1 with the following listed in order from bottom to top
starting with oak tree): primary producers, primary consumers, secondary consumers, and
tertiary consumers.

it provides an alternative energy pathway for the reaction to proceed.

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.

imagine a line passing through the center of earth that goes through both the north pole and the south pole. this imaginary line is called an axis. earth spins around its axis, just as a top spins around its spindle. this spinning movement is called earth's rotation. at the same time that the earth spins on its axis, it also orbits, or revolves around the sun. this movement is called revolution.