When the algorithm encounters an error, the message appears in the lab book (Figure ). A er player corrects all the errors and achieves ΔG < 0 by any permi ed means, "Submit" bu on is ac vated and the answer may be submi ed for analysis by the algorithm. Upon comple on of defined levels, certain chemicals will be unlocked and become available for use in all the following levels. For example, upon Level 1 comple on, H2O(l) will be unlocked (Figure ). Reward system. Upon submission of the solu on, the algorithm that is based on the rules of the game calculates the level score (Figure ). The level score is the sum of all bonuses: