Flames, lightning, and/of auroras.
Answer:
Substances with high boiling points condense at the bottom and substances with lower boiling points condense on the way to the top. The crude oil is evaporated and its vapours condense at different temperatures in the fractionating column.
Explanation:
answer above
Answer:
Exposure to oxygen (especially when combined with sunlight) alters the molecular structure of lignin, causing a change in how the compound absorbs and reflects light, resulting in the substance containing oxidized lignin turning a yellow-brown color in the human visual spectrum.