Final answer:
Trenches form at convergent plate boundaries, while mid-ocean ridges form at divergent plate boundaries. Trenches are created when two plates collide and one plate is forced beneath the other, while mid-ocean ridges form when two plates move apart and magma fills the gap, creating new crust.
Step-by-step explanation:
Trenches and mid-ocean ridges are both landforms that are created by plate tectonics, but they form at different types of plate boundaries.
Trenches are formed at convergent plate boundaries, where two plates collide. When an oceanic plate collides with a continental plate, the denser oceanic plate is forced beneath the continental plate, creating a trench. Examples of trenches include the Mariana Trench and the Peru-Chile Trench.
On the other hand, mid-ocean ridges form at divergent plate boundaries. These are places where two plates are moving apart from each other. As the plates separate, magma rises from the mantle and fills the gap, creating new oceanic crust. This process forms a ridge or mountain range underwater, such as the Mid-Atlantic Ridge.
Learn more about Plate Tectonics