What was the reason for spelling in chronicle?

There's no specific "reason" for the spelling "chronicle" as opposed to some other possible spelling. It's simply the way the word has evolved over time.

Here's a breakdown of its history:

* Origin: The word comes from the Old French word "chronique," which itself comes from the Greek word "chronikos" meaning "relating to time."

* Evolution: The "ch" sound at the beginning of "chronicle" reflects the Greek origin. The "le" ending is a common one in English words derived from French.

* Standardization: The spelling "chronicle" became standardized over time, likely influenced by its widespread usage in writing and printing.

So, the spelling "chronicle" isn't based on any particular reason besides historical development and the natural evolution of language.