Answer:
the first wave of extinction may be related to rapid cooling at the end of the Ordovician Period, and the second phase is widely regarded as having been caused by the sea-level fall associated with the glaciation.
Answer:
The activation energy must be reached. The catalyst makes lower energy pathways available.
Explanation:
<span>C) Haloalkanes (Halons) and Chloroflurocarbons (CFS's) are chemical gases that may be carried into the stratosphere, where the ozone layer resides. These chemicals react with ozone and cause a reaction that breaks ozone down into oxygen. Depletion of the ozone layer causes an increase in the ultraviolet radiation entering the earth.</span>
