How can you tell that mountain ranges are different ages?

Question

can anyone help me with this? I cant find a answer.

Answer 1

Old mountains- eroded, tree covered, rounded, lots of soil covering and vegetation, not capped with perpetual snowy peaks. (Appalachian)

Young mountains- tall, sharply pointed peaks, perpetual snow on top(usually), no trees, very little vegetation, often their peaks are hidden in clouds. (Rockies)

Answer 2

Mountains that are not as high as others and are covered in trees like the Appalachians are older than the higher rocky Rocky Mountains in the west.  The highest mountains on Earth were formed and are still growing higher over time. That range, the Himalayas are the result of two tectonic plates coming together.  The subcontinent of India is crashing into the continent of Asia and continues to push the Himalayas up even today. The highest mountains are the youngest.