How many moles of precipitate are formed when 25.0 mL of 1.00 M FeCl₃ reacts with 25.0 mL of 1.50 M AgNO₃ in the following chemical reaction?
FeCl₃ (aq) + 3 AgNO₃ (aq) → 3 AgCl (s) + Fe(NO₃)₃ (aq)

I'm learning about the periodic tables and what each subject's configuration is. for example, hydrogen is 1s^1, but i don't understand how you get that. can someone me understand how to figure out how to figure this out? sorry if the question makes no sense, but it would really a lot if you could me understand! you so much if you can!