1. Why are there active volcanoes along the Pacific coast in Washington and Oregon but not along the East coast of the United States?

The reason why there is intense geological activity in Washington and Oregon isbecause both states are part of what is known as the "Pacific ring of fire."  Allaround the Pacific Basin there are not only volcanoes but also tsunamis andearthquakes.  The San Andreas fault is another example of such geologicalactivity in California.  The study of plate tectonics applies here, and ismost interesting.

Because unlike Pacific coast, East coast is not along the sides of tectonic plates.