Kirchhoff's law of junction, $\Sigma I=0$, is based on

Kirchhoff's first law states that in an electric circuit, the algebraic sum of the currents meeting at any junction in the circuit is zero. i.e., $\quad \Sigma i=0$ Hence, according to Kirchhoff's law $i_1+i_2=i_3+i_4+i_5$ Thus, the sum of currents flowing towards the junction is equal to the sum of the currents flowing away from the junction. In other words, when a steady current flows in a circuit, then there is neither any accumulation of charge at any point in the circuit, nor any charge is removed from there. Thus, Kirchhoff's first law expresses the conservation of charge.