system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are chemical formulas in the order they are? Why is it H2O and not OH2? Why is it C6H12O6 and not O6H12C6?
gpt
There are multiple ways of listing chemical formulas. The most commonly used notation is the "Hill system". It is carbon first, then hydrogen, then alphabetically.  It is done that way to make it consistant and easier to read.