Where do most earthquakes occur? Where do most volcanoes occur? Why do they occur here?

Most earthquakes occur along the edge of the oceanic and continental plates. The belt exists along boundaries of tectonic plates, where plates of mostly oceanic crust are sinking beneath another plate.

Most volcanoes are found along a belt, called the “Ring of Fire” that encircles the Pacific Ocean. As the plates move, they spread apart, collide, or slide past each other. Sixty percent of all active volcanoes occur at the boundaries between tectonic plates.

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.