How many molecular orbitals are formed when one 1s orbital of hydrogen combines with four atomic orbitals of element X?

When one 1s orbital from hydrogen combines with four atomic orbitals from element X, the total number of atomic orbitals being combined is five (one from hydrogen and four from element X). In molecular orbital theory, the combination of atomic orbitals to form molecular orbitals follows the principle that the number of resulting molecular orbitals is equal to the number of combined atomic orbitals.

Thus, when considering the one 1s orbital from hydrogen and the four orbitals from element X, they will combine to produce five molecular orbitals. This principle applies to both bonding and antibonding molecular orbital formation, where the molecular orbitals created are directly correlated to the number of atomic orbitals involved in the mixing.

This is consistent with the fundamental rules of molecular orbital theory, which state that the number of molecular orbitals must equal the number of atomic orbitals used in the combination process. As a result, five molecular orbitals will be formed in this scenario.