It's a salt of carbonic acid. it's called sodium bicarbonate. It contains the anion HCO3. It usually refers to bicarbonate of soda (baking soda), a white powder that is a common ingredient in antacids. It is also a byproduct of your body's metabolism.
Check that in your book it will be easy to find it!
India’s geography contributed to its isolation from the rest
of Asia. It is a peninsula but on the North, the Himalayas shields it from
invasion of both men and ideas. On the East there are dense forests that
although have lower height, is infested with malaria. Great oceans surround the
south and mountain ranges that are difficult to traverse block the West. As a
result, the Indian community developed its caste system, the most elaborate
expression in history of an unmoving agricultural society.
