The ph of the blood is strengthened by the carbonic acid being in equilibrium with the dissolved CO2 in the blood. D. Acid Rain involves nitric and sulphuric acid. Each one forms when their oxides form with water vapor. An oxide is a compound consisting of oxygen and usually one other element. The oxidation number of oxygen is -2 in oxides.
Oxides are usually stable.
They are produced naturally by volcanos. Man-made ways to produces sulphur oxides are by combustion of high sulphur coal and oil and smelting of sulphur containing ores. Centigrade is less dense and floats above water at 4 degrees. There is stratification and fall and winter overturn of the column of water. There are three layers in the column.