Carbonic acid equilibrium reaction (stoichiometry or reality)?

H2O + CO2 ⇌ H2CO3 is stoichiometrically correct. Without the involvement of at least one water molecule on the right-hand side, the conversion of carbonic acid into water and carbon dioxide cannot actually be represented (would a carbonic acid molecule ever decompose itself and completely restructure itself in a vacuum?). Shouldn't the reaction equation therefore…

Working with ordered lists in math: How do I write something down?

Hello! ^w^ I'm currently doing something with lists in math. However, I only have a basic understanding of how to write them in Desmos. But, for example, How do I record the length of a list? How do I record the mean value, the sum of the elements, and the nth element? I have absolutely…