<span>The addition of a catalyst to a chemical reaction provides an alternate pathway that c</span>atalysts lowers the activation energy.
Answer: Arsenic has five valence electrons.
Explanation: Good luck!
An extinction event is a widespread and rapid decrease in the biodiversity on Earth. Such an event is identified by a sharp change in the diversity and abundance of multicellular organisms. It occurs when the rate of extinction increases with respect to the rate of speciation. -Wikipedia
