Question On The Chase....

[ToraToraTora]

What element accounts for arond 65% of the human body? Calcium, hydrogen or oxygen.
Now we know that the body is 60-70% water and water is H2O ie 2 Hydrogen atoms to 1 oxygen right? So the answer must be Hydrogen, right? Wrong! the answer was Oxygen. Can someone explain how?

[douglas9401]

https://askabiologist.asu.edu/content/atoms-life

[Sqad]

Good point TTT.

Water is a compound and should not be considered.
Oxygen is an element and makes up around 60% of body by mass.
Oxygen is the correct answer.

[gingejbee]

....but one oxygen atom weighs many times more than two hydrogen atoms...

[Calibax]

Question probably asking about mass rather than number of atoms. Although water contains twice as many hydrogen atoms as oxygen, an oxygen atom is 16 times heavier than a hydrogen atom.

[ToraToraTora]

right so we re saying that by weight it's oxygen because they are heavier than hydrogen, right! I see

[ToraToraTora]

Thanks all, I see now I had not considered the mass of the atoms concerned.