What causes some mountain ranges to be volcanic and other mountain ranges to not be volcanic?

Movements of tectonic plates create volcanoes along the plate boundaries, which erupt and form mountains. A volcanic arc system is a series of volcanoes that form near a subduction zone where the crust of a sinking oceanic plate melts and drags water down with the subducting crust

Most volcanoes occur in a band encircling the Pacific Ocean (the Pacific Ring of Fire), and in another that extends from the Mediterranean across Asia to join the Pacific band in the Indonesian Archipelago. The most important types of volcanic mountain are composite cones or stratovolcanoes

The reason that not all mountains are volcanic is because most mountains form by the crust of the earth buckling as tectonic plates collide. The Himalayas, the European Alps, and the New Zealand Southern Alps are all examples of non-volcanic mountain chains caused purely by collision of continental crust at plate boundaries.

Volcanoes can also form from the collision of plates, but, for the most part, volcanoes need a subduction zone interface at the plate boundary. The Andes in South America, the Canadian Rockies and the Aleutian Arc, Japan, Kamchatka, Indonesia are all examples of subduction-related 'Volcanic Arcs'. The volcanoes in these arcs can appear along with mountains formed by collision.

Volcanoes can also occur at mid-ocean ridges, or as related to hotspots. Iceland is a good example of a combination of a mid-ocean ridge and a hotspot, while Hawaii is a good example of a hotspot only. Another hotspot-related volcano is Yellowstone, even though it forms within mountains created by buckling of the crust.

Movements of tectonic plates create volcanoes along the plate boundaries, which erupt and form mountains. A volcanic arc system is a series of volcanoes that form near a subduction zone where the crust of a sinking oceanic plate melts and drags water down with the subducting crust.

Location of these mountain ranges along the plate boundaries.

Explanation:

Over 90 percent of world's volcanoes are located along the plate boundaries which are created due to the movement of tectonic plates. For example, Pacific Ring of Fire formed near the zone of downward movement of earth's crust.

But other mountain ranges are not volcanic in origin as the are formed due to folding of earth's crust. For example, Himalayas, Alps, etc.