Final answer:
Mountain chains differ due to tectonic activities that create them and erosion over time. the Himalayas and Rockies are young and jagged, formed by plate collisions. the older Appalachians have been smoothed by extensive erosion.
Step-by-step explanation:
The differences between mountain chains like the tall, sharply peaked Himalayas and the Rockies, and the relatively flat and rounded Appalachians result from both the geologic processes that form them and the subsequent erosion they experience over time.The Himalayas and the Rockies were formed through tectonic plate collisions, which caused the earth to push upwards, forming mountain chains. this activity can still be ongoing, contributing to the young and jagged nature of these mountain ranges.
In contrast, the Appalachians were formed much earlier and have been extensively eroded, resulting in their more rounded mountains today.Erosion plays a key role in shaping mountains. Ice, water, and weathering processes wear away at the rock, smoothing out the landscape over millions of years. The sharp peaks of younger mountain ranges have not yet been as significantly eroded, whereas the longer exposure of the Appalachians to erosional forces has resulted in their comparatively gentle slopes.J11