Final answer:
Tobacco is a plant that contains nicotine and is widely used for its stimulating effects. However, tobacco smoke also contains carcinogenic chemicals that increase the risk of cancer.
Step-by-step explanation:
Tobacco is a plant that is widely used for its stimulating and relaxing effects, primarily due to the presence of nicotine. However, tobacco smoke contains numerous chemicals that have been proven to be carcinogens or causes of cancer. Some of the most potent carcinogens in tobacco smoke include benzopyrene, acrolein, and nitrosamines, as well as radioactive isotopes like lead-210 and polonium-210.