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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, in a similar way to the planets that go around the Sun. The electron cloud model says that we can't know exactly where an electron is at any given time, but the electrons are more likely to be in specific areas. This is the most modern and accepted way to describe the situation.
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.