आम्ल वर्षाचे pH मूल्य काय असते? A. 5.5 किंवा कमी B. 12.5 किंवा अधिक C. 10.5 किंवा अधिक D. 8.5 किंवा अधिक

Normal rain is slightly acidic (pH about 5.6) because of dissolved CO₂. Rain with a pH of about 5.5 or lower is called acid rain; it is caused by sulphur dioxide and nitrogen oxides forming acids in the air.