Background: Like water in the ocean, air in the atmosphere exerts pressure that increases with depth. Most gas molecules in the atmosphere are pulled close to Earth’s surface by gravity. As a result, air pressure decreases quickly at lower altitudes and then more slowly at higher altitudes. This is illustrated in Figure below . Air pressure is greatest at sea level, where the depth of the atmosphere is greatest. At higher altitudes, the pressure is less because the depth of the atmosphere is less. For example, on top of Mount Everest, the tallest mountain on Earth, air pressure is only about one-third of the pressure at sea level. At such high altitudes, low air pressure makes it hard to breathe and is dangerous to human health.

Situation: Beth was having a great time at the ski resort but after a day of skiing on the mountains but she head a headache now and was feeling light headed. Maybe she would feel better when they went to the village in the valley tomorrow.

Question: was the air pressure higher on the mountain or in the valley?

Situation: Beth was having a great time at the ski resort but after a day of skiing on the mountains but she head a headache now and was feeling light headed. Maybe she would feel better when they went to the village in the valley tomorrow.

Question: Was the air pressure lower on the mountain or in the valley?

Situation: Beth was having a great time at the ski resort but after a day of skiing on the mountains but she head a headache now and was feeling light headed. Maybe she would feel better when they went to the village in the valley tomorrow.

Question: Does the air pressure decrease more quickly on the mountain or in the valley?

Situation: Beth was having a great time at the ski resort but after a day of skiing on the mountains but she head a headache now and was feeling light headed. Maybe she would feel better when they went to the village in the valley tomorrow.

Question: Does the air pressure decrease slower on the mountain or in the valley?

Situation: Beth was having a great time at the ski resort but after a day of skiing on the mountains but she head a headache now and was feeling light headed. Maybe she would feel better when they went to the village in the valley tomorrow.

Question: Is the depth of the atmosphere higher on the mountain or in the valley?

Situation: Beth was having a great time at the ski resort but after a day of skiing on the mountains but she head a headache now and was feeling light headed. Maybe she would feel better when they went to the village in the valley tomorrow.

Question: Is the depth of the atmosphere lower on the mountain or in the valley?

Situation: Beth was having a great time at the ski resort but after a day of skiing on the mountains but she head a headache now and was feeling light headed. Maybe she would feel better when they went to the village in the valley tomorrow.

Question: Is easier to breath on the mountain or in the valley?

Situation: Beth was having a great time at the ski resort but after a day of skiing on the mountains but she head a headache now and was feeling light headed. Maybe she would feel better when they went to the village in the valley tomorrow.

Question: Is harder to breath on the mountain or in the valley?

Situation: Beth was having a great time at the ski resort but after a day of skiing on the mountains but she head a headache now and was feeling light headed. Maybe she would feel better when they went to the village in the valley tomorrow.

Question: Is easier to get enough oxygen on the mountain or in the valley?

Situation: Beth was having a great time at the ski resort but after a day of skiing on the mountains but she head a headache now and was feeling light headed. Maybe she would feel better when they went to the village in the valley tomorrow.

Question: Is harder to get enough oxygen on the mountain or in the valley?

Situation: Mark had looked forward to climbing Mt. Denalit for years. Today he would complete the last leg and be on top op the mountain more than 20,000 miles above sea level. As the day went on Mark often had to slow down as he was getting light headed and tired.

Question: Was the air pressure higher or lower when Mark started the last leg?

Situation: Mark had looked forward to climbing Mt. Denalit for years. Today he would complete the last leg and be on top op the mountain more than 20,000 miles above sea level. As the day went on Mark often had to slow down as he was getting light headed and tired.

Question: Was the air pressure higher or lower when Mark was at the base of the mountain?

Situation: Mark had looked forward to climbing Mt. Denalit for years. Today he would complete the last leg and be on top op the mountain more than 20,000 miles above sea level. As the day went on Mark often had to slow down as he was getting light headed and tired.

Question: Was the air pressure higher or lower when Mark was at the sumit??

Situation: Mark had looked forward to climbing Mt. Denalit for years. Today he would complete the last leg and be on top op the mountain more than 20,000 miles above sea level. As the day went on Mark often had to slow down as he was getting light headed and tired.

Question: Was the air pressure increasing or decreasing as Mark climbed??

Situation: Mark had looked forward to climbing Mt. Denalit for years. Today he would complete the last leg and be on top op the mountain more than 20,000 miles above sea level. As the day went on Mark often had to slow down as he was getting light headed and tired.

Question: Would the air pressure be  increasing or decreasing as Mark decended the mountain?

Situation: Mark had looked forward to climbing Mt. Denalit for years. Today he would complete the last leg and be on top op the mountain more than 20,000 miles above sea level. As the day went on Mark often had to slow down as he was getting light headed and tired.

Question: Is the depth of the air increasing or decreasing as mark climbs??

Situation: Mark had looked forward to climbing Mt. Denalit for years. Today he would complete the last leg and be on top op the mountain more than 20,000 miles above sea level. As the day went on Mark often had to slow down as he was getting light headed and tired.

Question: Will the depth of the air be increasing or decreasing as Mark decendsthe mountain?

Situation: Mark had looked forward to climbing Mt. Denalit for years. Today he would complete the last leg and be on top op the mountain more than 20,000 miles above sea level. As the day went on Mark often had to slow down as he was getting light headed and tired.

Question: Will it get easier or harder to breath as Mark decendsthe mountain?

Situation: Mark had looked forward to climbing Mt. Denalit for years. Today he would complete the last leg and be on top op the mountain more than 20,000 miles above sea level. As the day went on Mark often had to slow down as he was getting light headed and tired.

Question: Is air pressure decreasing faster at the base or summit of the mountain?

Situation: Mark had looked forward to climbing Mt. Denalit for years. Today he would complete the last leg and be on top op the mountain more than 20,000 miles above sea level. As the day went on Mark often had to slow down as he was getting light headed and tired.

Question: Is air pressure decreasing slower at the base or summit of the mountain?

Situation: Mat loved being outside and being physically active. So he took every opportunity to go mountain climbing. Last year he went on two climbs. The first A was challenging but lots of fun. On his second climb B he had some trouble though. Near the top of the mountain he was having trouble breathing he got very light headed and was not able to continue.

Question: Which mountain was lower?

Situation: Mat loved being outside and being physically active. So he took every opportunity to go mountain climbing. Last year he went on two climbs. The first A was challenging but lots of fun. On his second climb B he had some trouble though. Near the top of the mountain he was having trouble breathing he got very light headed and was not able to continue.

Question: Which mountain was higher?

Situation: Mat loved being outside and being physically active. So he took every opportunity to go mountain climbing. Last year he went on two climbs. The first A was challenging but lots of fun. On his second climb B he had some trouble though. Near the top of the mountain he was having trouble breathing he got very light headed and was not able to continue.

Question: At the top of wich mountain was the air pressure highest?

Situation: Mat loved being outside and being physically active. So he took every opportunity to go mountain climbing. Last year he went on two climbs. The first A was challenging but lots of fun. On his second climb B he had some trouble though. Near the top of the mountain he was having trouble breathing he got very light headed and was not able to continue.

Question: At the top of wich mountain was the air pressure lowest?

Situation: Mat loved being outside and being physically active. So he took every opportunity to go mountain climbing. Last year he went on two climbs. The first A was challenging but lots of fun. On his second climb B he had some trouble though. Near the top of the mountain he was having trouble breathing he got very light headed and was not able to continue.

Question: Which mountain is closest to sea level?

Situation: Mat loved being outside and being physically active. So he took every opportunity to go mountain climbing. Last year he went on two climbs. The first A was challenging but lots of fun. On his second climb B he had some trouble though. Near the top of the mountain he was having trouble breathing he got very light headed and was not able to continue.

Question: Which mountain is highest from sea level?

Situation: Beth had been practicing for this climb for a long time. She had started out at the base a few days ago and would reach the summit before night.  She had had to slow down as she moved up the mountain because she found it harder to breath but overall it had been a good experience.

Question: is the air pressure higher or lower at the top of the mountain?

Situation: Beth had been practicing for this climb for a long time. She had started out at the base a few days ago and would reach the summit before night.  She had had to slow down as she moved up the mountain because she found it harder to breath but overall it had been a good experience.

Question: is the air pressure higher or lower at the base of the mountain?

Situation: Beth had been practicing for this climb for a long time. She had started out at the base a few days ago and would reach the summit before night.  She had had to slow down as she moved up the mountain because she found it harder to breath but overall it had been a good experience.

Question: Does the depth of the atmosphere increase or decrease as Beth climbs the mountain?