How practice works
Earn 10 / 20 / 30 points for a new Easy / Medium / Challenge reaction. Each hint costs 2 potential points (minimum 2). Learn Mode has six unscored tutorial lessons. A wrong check, skipping an unfinished practice reaction, or leaving it for Learn ends your streak. Resetting coefficients keeps your hints and attempts. Previously solved reactions are review only.
Progress is saved in this browser on this device. No account, no data sent to a server. Reaction conditions and physical states are omitted to focus on balancing; this is not a lab procedure.
Background reading: OpenStax: Writing and balancing chemical equations.