In chemistry and nuclear physics, the electron cloud is a way to describe where electrons are when they go around the nucleus of an atom. The electron cloud model is different from the older model by Niels Bohr. Bohr talked about electrons going around the nucleus in a fixed circle, the same way that planets go around the Sun. The electron cloud model says that we can not know exactly where an electron is, but the electrons are more likely to be in specific areas of an atom. It is the most modern and accepted form of the atom.
In the Bohr model, electrons were assigned to different shells. These shells explained the repeating patterns of chemical properties in the periodic table. Using quantum mechanics, chemists can use the electron cloud model to assign electrons to different atomic orbitals. These atomic orbitals are not all spheres. Atomic orbitals also explain the patterns in the periodic table.
It was developed in 1926 by Ernest Schrödinger and Werner Heisenberg. The model provides the means of visualizing the position of electrons in an atom.