The concept of electron clouds, regions where electrons are likely to be found, emerged from the collective work of several key 20th-century physicists. Niels Bohr's model of quantized electron orbits laid the groundwork, which was expanded by Louis de Broglie's wave-particle duality. Erwin Schrödinger's wave equation provided a mathematical framework, while Werner Heisenberg's Uncertainty Principle highlighted the probabilistic nature of electron positions. Max Born's interpretation of the wave