Enzymes are organic catalysts
and catalysts generally increase rate of reaction by lowering activation energy
C is the answer
The main pieces of evidence that an exothermic reaction has occurred is an increase in temperature due to the release of energy, a release of energy in the form of light, or a release of gas.
That specific kind is called gas.
When you put water in a freezing temprature it becomes solid.
When you boil water it becomes gas
Solar- the sun is not always shining, for example at night you can't get any energy from the sun
Wind-it's not always windy
Water- there can be drought
Really the main issue of all three of these is that they are not always available
Both are oxidation reactions. Burning is just a lot faster than rusting.
