Answer:
Excess Reagent = oxygen
Explanation:
Limiting reagent: The substance that is totally consumed when the reaction is completed.
Excess reagent: The substance left after the limiting reagent is consumed completely
The balanced chemical equation for formation of water is as follow:

This means when 2 moles of hydrogen reacts with 1 mole of oxygen, 2 moles of water is produced.
Hence the ratio in which hydrogen and oxygen gas reacts is 2:1
Now if 2 mole hydrogen require 1 mole of oxygen ,then 4 mole hydrogen need 2 mole of oxygen.

or

Here 5 mole of oxygen is reacting but only 2 mole is required .
Oxygen is in excess.
The pH of normal rainwater is 5.6. It's slightly acidic
Answer:
Outside air
Nose
Lungs
Bloodstream
Cell
Explanation:
We breathe in oxygen from the outside air in through our nose and it travels to our lungs. Inside our lungs, we have Avioli's that diffuse oxygen into our bloodstream and the bloodstream helps the oxygen travel into our cells.
Hope this helps :)
1.000.000 is the correct answer