HISET Social Studies Practice 2025 - Free HISET Social Studies Practice Questions and Study Guide

The formation of mountains is primarily attributed to the movement of tectonic plates. This process occurs at the boundaries of tectonic plates where they can collide, pull apart, or slide against each other. When two continental plates merge, for instance, they can buckle and fold, leading to the creation of mountain ranges like the Himalayas. This tectonic activity is a fundamental process in shaping the Earth's landscape and is responsible for the formation of many of the world's most prominent mountain ranges.

While volcanic activity can also lead to the formation of mountains through the eruption of magma that builds up around a volcano, this is not the primary process for most mountain ranges. Erosion, on the other hand, can modify and wear down existing mountains over time, but it does not create new ones. Similarly, glacier expansion can carve out valleys and reshape landscapes but is not directly responsible for mountain formation itself.