Because the air is thinner up there. There is less oxygen in the air, so it is harder to breathe.
At high altitudes, the air pressure is lower, which means that there is less oxygen available per breath. This makes it harder for the body to take in enough oxygen to meet its needs, resulting in difficulty breathing at the top of a mountain.
There is less air pressure at the top of the mountain which means that all the air molecules you are trying to breathe are farther apart than they are at sea level which makes it seem like it is harder to breathe because you aren't getting quite as much as you're used to. To counter this your body creates a larger number of red blood cells and increases their size so they can transport more oxygen throughout your system.
Mount Everest is the highest mountain on Earth above sea level, with a summit elevation of 29,032 feet (8,848 meters).
K2, the second-tallest mountain in the world, is 8,611 meters (28,251 ft) above sea level.
The tallest mountain in the world is Mount Everest It is about 5.5 miles (8.9 kilometers) above sea level."
Air is thinner. So until you are used to it -it feels difficult
At high altitudes, the air pressure is lower, which means that there is less oxygen available per breath. This makes it harder for the body to take in enough oxygen to meet its needs, resulting in difficulty breathing at the top of a mountain.
At sea level, the atmospheric pressure is higher, which compresses the air and allows more oxygen molecules to be present in each breath. As you go higher in the atmosphere, the air pressure decreases, reducing the density of oxygen and making it harder to breathe in enough oxygen with each breath.
sea level
Driskill Mountain, Louisiana is 535 feet above sea level
Sea level
At sea level
Mauna Kea in Hawaii is the tallest mountain on Earth when measured from base to summit. While not the tallest above sea level, its base is located below sea level, making it the largest mountain below sea level.
A mountain peak above sea level is simply called a "mountain peak" or "summit." It is the highest point of elevation on the mountain.
No, it would be harder to breathe on top of Mount Whitney (or any other mountain) do to the air being thinner. The thin air at higher elevations has less oxygen in it than at sea level (air at 10,000 to 14,000 ft has only 60-70 percent of the amount of oxygen in the air at sea level). Therefore with each breath you don't get much oxygen.
The height of a mountain peak above sea level is called its elevation.
That depends on your definition of "mountain".