Remundo wrote:it is quite true that rainwater is naturally demineralized, and drinkable, unless it passes through polluted "clouds".
It is the air that is polluted. I have some data that have evaluated the amount of nitrogen contained in rainwater at about ten units per ha (of memory) - but it is far to be peanuts! You add sulphates from SO² ...
Add to this what is collected on the roofs (where there are enough minerals for lichens to grow!) ...
So yes, the rainwater is no longer pure.
I do not know if anyone has serious and complete rainwater analyzes (because we only find what we are looking for, we should not see a lot of calcium!).
There it is :
What does rainwater contain?
Analyzes are carried out very regularly in the laboratories to know exactly the composition of the rainwater. This contains:
Sulphate (SO4²): molecule based on sulfur. It is contained in most products, consumables or not. The average amount of sulphate in rainwater is 9,5 mg / L.
Calcium (CA²): a very common chemical component that contributes to bone growth. Rainwater contains on average 21 mg of calcium per liter.
Potassium (K +): a chemical element that is vital for the functioning of animal cells. Its quantity is of the order of 0,8 mg / L.
Chloride (Cl-): atom charged with electrons. Rainwater is dosed at 9 mg / L.
Sodium (Na +): mineral essential to the body. Its value is estimated at 1,6 mg / L.
Nitrate (NO3): chemical substance from pollution. The average rate is 1,6 mg / L. But it can reach locally up to 5 mg / L (heavily agricultural or industrialized regions).I hope the figures are serious, because the comments (chlorine, an "atom charged with electrons" blah blah - every anion has gained one or more electrons, every cation has lost some).