In order to derive the nitrogen cycle, each student in the class takes the role of a nitrogen atom, beginning the activity in the form of NO3 -, amino acid, N2, etc. Eight stations are set up around the classroom representing different nitrogenous molecules; students travel between stations according to instruction cards drawn randomly at each station. For example, a student acting as NO3 - may learn that via denitrification, she's been reduced to 1/2N2. She would proceed to the N2 (gas) station, where she may be fixed biologically, reduced abiologically, or remain as N2 for another turn. After 10 to 12 turns (as time allows), students gather in small groups to compare their unique "voyages." (Instruction cards are included in Appendix I.)