Electric Charge

Charge is a fundamental property of matter. Two types: positive (protons) and negative (electrons). Like charges repel, unlike attract. Charge is quantized: q = ne (n is integer, e = 1.6×10⁻¹⁹ C). Charge is conserved: total charge in isolated system is constant. SI unit: Coulomb (C). 1 C is very large — typical charges are μC or nC.