If you add the valences of each atom in the molecular formula for arsenious acid, H 3 AsO 3, you can see that the molecule, which is uncharged, has a total valence state of 0 (3x(+1) for the hydrogen atoms; 1x(+3) for the arsenic(III) atom; 3x(-2) for the oxygen atoms = 3+3-6 = 0).
Eighty percent of sewage in India is untreated and flows directly into the nation's rivers, polluting the main sources of drinking water, a study by an environment watchdog showed Tuesday.
Majority of rivers of India are facing acute water pollution problems and river Yamuna is one of them. Due to excessive industrialization and urbanization of river Yamuna especially in Delhi, Mathura and Agra have now become a drain. The water pollution of the river has gained large heights.