Yes, it is possible to have an atom with only one orbital electron. In fact, hydrogen, the simplest and most abundant element in the universe, consists of a single proton in its nucleus and one electron orbiting around it. Hydrogen is an example of an atom with only one electron.
The behavior and properties of an atom are determined by the arrangement of its electrons in various orbitals around the nucleus. Each orbital can hold a specific number of electrons, depending on its energy level and quantum properties. In the case of hydrogen, the electron occupies the lowest energy level, known as the 1s orbital.
It's important to note that atoms with more than one electron can have more complex electron configurations with multiple orbitals and energy levels. However, the concept of an atom with a single orbital electron is certainly valid and can be observed in the case of hydrogen.