I'd like to suggest and ask more about impedance, like

What's the voltage across the capacitor in an AC series circuit?

And what's the voltage across the resistor?

And I'd like to ask the same for inductor, which is, probably, the inverse.

And about the instant energy being stored in a capacitor (instantaneous voltage times the instantaneous current), I'd like to say that I've made a lot of progress about it, if you need my help, I'd be glad to help build this site.