1, And that 1 is THC (Tetrahydrocannabinol) is the only Chemical in Ganja.
And it is THC that gets you high.
There are many different chemicals present in cigarettes but the drug Nicotine is what makes them addictive.
4000 different chemicals are in one cigarette
yes, sciene may duplicate many chemicals present in human body but not all.
No set answer. Depends on the individual. There are chemicals that appear in the brain naturally, and then there are chemicals (drugs, medicines, toxins, etc.) that are put into the bloodstream from outside sources.
Well... yes. Many different chemicals make many different "things" work. For example, the common chemical water makes you work.
There are many different solvents and many different chemicals which may or may not mix with a given solvent. Your question is too general.
Many different chemicals with different names are used as fertilizers; there's no one scientific name for them.
Many different chemicals burn and produce flames, but different chemicals have different chemical properties, and produce different amounts of energy when they burn. Those which produce more energy, will also produce hotter flames.
Four.
Crude oil is a complex mixture of a great many different chemicals.
some brands are soaked in over 4000 different chemicals (marlboro)
Various different ways, usually using many different chemicals and mixtures that are neutralized and then tested on animals/humans