Within a single atom, the atomic orbitals do not overlap or combine with each other. Atomic orbitals are individual regions of space where electrons are likely to be found. They are defined by specific quantum numbers (such as the principal quantum number, azimuthal quantum number, and magnetic quantum number) that determine their size, shape, and orientation.
Each atomic orbital is associated with a particular energy level and has a distinct spatial distribution. For example, the 1s orbital is spherical and centered around the nucleus, while the 2s orbital is larger and more diffuse, and the 2p orbitals are dumbbell-shaped with different orientations.
While these orbitals may occupy the same general region of space around the nucleus, they do not physically combine or merge with each other. Instead, they exist as separate entities, each capable of accommodating a specific number of electrons.
However, when atoms come together to form molecules through chemical bonding, the atomic orbitals can interact and overlap with the orbitals of other atoms. This leads to the formation of molecular orbitals, which extend over multiple atoms. Molecular orbitals are the result of combining and reshaping atomic orbitals to accommodate the sharing of electrons between atoms in a molecule.
In summary, atomic orbitals within a single atom do not overlap or combine with each other. They remain distinct entities with their own characteristics. It is when atoms combine to form molecules that the atomic orbitals can interact and form molecular orbitals.