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.
India is the world's third biggest greenhouse gas emitter (not including the European Union) but has pledged to source 40% of its electricity from renewable and low-carbon sources by 2030. The country is home to 13 of the 20 most polluted cities in the world, according to a World Health Organization report.