AP BIOLOGY

Detailed explanation-1: -Hydrogen sulfide is found in coal pits, volcanic gases, natural gas wells, sulfur springs, and decaying organic matter which contains sulfur.

Detailed explanation-2: -It occurs naturally in crude petroleum, natural gas, and hot springs. In addition, hydrogen sulfide is produced by bacterial break-down of organic materials and human and animal wastes (e.g., sewage).

Detailed explanation-3: -Hydrogen sulfide indicates volcanic activity is relatively quiet. When sulfur gases are released from magma and encounter groundwater as they rise, the sulfur can react with water and form hydrogen sulfide (H2S).

Detailed explanation-4: -Hydrogen sulfide (H2S) is a colorless gas with the odor of rotten eggs. The most common sources of H2S emissions are oil and natural gas extraction and processing, and natural emissions from geothermal fields.

Detailed explanation-5: -Most hydrogen sulfide in the air comes from natural sources. It is produced when bacteria break down plant and animal material, often in stagnant waters with low oxygen content such as bogs and swamps. Volcanoes, hot springs and underwater thermal vents also release hydrogen sulfide.