Which element has a higher atomic number than uranium but is not naturally occurring?

The correct identification of the element with a higher atomic number than uranium that is not naturally occurring is plutonium. Plutonium has an atomic number of 94, which is higher than uranium’s atomic number of 92. It is primarily produced artificially in nuclear reactors through the irradiation of uranium-238 and does not exist in significant amounts in nature due to its radioactive nature and the fact that it is primarily created as a byproduct of nuclear fission.

Lanthanum, on the other hand, has an atomic number of 57, which is lower than uranium’s atomic number. Neptunium, with an atomic number of 93, is higher than uranium but is typically considered one of the transuranium elements that can occur in trace amounts in nature through neutron capture but is primarily produced artificially. Curium, with an atomic number of 96, also does not occur in nature in significant amounts and is produced only in nuclear reactions.

Thus, while the other elements may have different relationships to uranium's atomic number or natural occurrence, plutonium distinctly meets the criteria set out in the question as the element with a higher atomic number than uranium that is not naturally occurring.