Question: what are the physical and chemical properties of nicotine?
Answer: In its pure state it is a colourless, odourless liquid with an oily consistency, but when exposed to light or air, it acquires a brown colour and gives off a strong odour of tobacco. Nicotine's chemical formula is C10H14N2. Nicotine is the chief addictive ingredient in the tobacco used in cigarettes, cigars, and snuff.