A large percent of mountains are part of chains that take up a significant part of the globe. However there are mountains that are not part of mountain chains, for example: Mt. Kilimanjaro. Most mountains are above water, however Hawaii for example has the largst mountains in the world, they just aren't completly above land.
Largest American Mountains:
20,320 ft. Mt. Mckinley (Denali)
19,470 ft. Mt. Mckinley north Tower
18,008 ft. Mt. St. Elias
17,400 ft. Mt. Foraker
16,500 ft. Mt. Bona
16,390 ft. Mt. Blackburn
Largest Mountain per continent
Africa: Mt. Kilimanjaro 19,340 ft.
Antarctica: Vinson Massif 16,864 ft.
Asia: Mt. Everest 29,028 ft.
Australia: Mt. Kusciosko 7,310 ft.
Europe: Mt. Elbrus 18,510 ft.
North America: Mt. Mckinley
South America: Mt. Aconcagua 22,834 ft.