In the English language, the word scent is used specifically for a kind of smell that is pleasant or has fragrance.
On the other hand, in the English language, the word smell is used to describe any kind of odour. The odour might be pleasant or not pleasant. It can be good as well as bad. Smell refers to any kind of smell which our olfactory receptors can determine.
Water is the single source as it provides the electrons by splitting into oxygen and hydrogen. This process happens during the light-dependent reactions.
