if a water molecule has 1 atom of oxygen how come we can't breath underwater?

Question

nothing

Answer 1

The oxygen in water is different from the oxygen we breathe in. The oxygen we inhale is in fact present in water. However, we lack the special organs (gills) that can filter the oxygen out of water. If we try to breathe in water, water will fill our lungs and prevent air from entering through our alveoli into our bloodstream. This will result in drowning.

Answer 2

alexjcharlton comes the closest, but not quite on the mark.

Fish don't separate the oxygen from the H2O. This requires too much energy. The gills utilize the dissolved oxygen in the water. Fish can "drown" in water if the dissolved oxygen drops to too low of a level. This occurs occasionally in small bodies of water during the summer. Warm water can't hold as much dissolved oxygen as cold water.

The lungs aren't set up to handle water simply because water is too thick a fluid for them to handle. They won't collapse from inhaling water but can't get the water in and out fast enough, even if they could access the dissolved oxygen.

Temperature would also be very important. The specific heat of water is much higher than air. Cold water would cause hypothermia. Water too warm would cause hyperthermia. It would have to be just right. (Why did Goldilocks just come to mind?)

Answer 3

OK, absolutely the last question I'm answering before I got to bed (have been saying that for an hour now!)

The only real way to separate water into oxygen and hydrogen would be electrolysis, which would require some really specialized equipment and means of generating quite a lot of electricity. Needless to say, this is not something your lungs can do.

Water does have oxygen dissolved in it which you could theoretically breathe (your lungs really aren't too different from gills.) The only reason we drown when water gets into our lungs is that the change in pressure causes our lungs to collapse and because the insides are sticky they won't open again and we die.

Answer 4

Interestingly, there is enough oxygen dissolved in cold water to sometimes keep alive drowned victims for much longer than the "normal" six minutes after which usually one's brain dies from oxygen starvation.

Evidently small children can last longer, probably due to their brain's lesser requirement for oxygen.

I also understand that when you drown, once your lungs are full of water, it is not a painful death any more. When you hold your breathe, the discomfort is from the buildup of CO2 in the blood, not the lack of oxygen. Once the drowner has lungs full of water, he/she just gradually loses consciousness before dying.

Not that I will want to test this out.

Answer 5

because your lungs aren't designed to separate the oxygen from the hydrogen in a water moledule. oxygen in air is in the form of O2. There's not enough O2 dissolved in water (not in the form of H2O) to breathe.

Answer 6

Because our lungs cannot process and extract the oxygen from the water. In addition, the make-up of water is not anything that we could process. Also, water is heavy enough to deluge the air sacs in our lungs and could possibly rupture them. The process of extracting the water and bringing in new water is too complicated for our respiratory system....which is why gills pass thru body and then the 'used' water is expelled with new water easily passing thru. (i.e. Fish)

Answer 7

the reson is that your body has no means of spliting the oxygen from the h20 (water) molecule, and if it did you could you would be breathing water (prosses cant be that fast) and hydrogen (by product).

Answer 8

because hydrogen dominates over oxygen changing its properties of density hence making it non-breathable. But you can breathe in liquid oxygen mixed with proper amount of nitrogen and hydrogen.

Answer 9

cuz we can't only breath in the oxegen we would breath in the water too