Kirchhoff's junction rule, that the sum of currents entering a junction equals the sum leaving it, is a direct consequence of

1. In steady state there is no accumulation of charge at a junction. 2. So the rate of charge flowing in must equal the rate flowing out. 3. This is exactly conservation of charge applied to the junction. 4. The loop rule, not the junction rule, follows from energy/potential considerations (A, C). _Source: syllabus Physics Ch 3 "Current Electricity", p.16_