Press 1 to call H to your pointer, 2 for O, 3 for C, 4 for N. Click and hold to push away certain particles (H,O,C,N,H2,O2,H2O) Press space to lay a + station. Hold 0 to clear compounds and + stations and recenter core elements.
I took gochris10's awesome project and added a cool movement for Hydrogen, Oxygen, and Nitrogen (on their own). Hold the mouse to call them. Note: This project is temporary, and will serve just as a way for gochris10 to use my new code in his element sim.