According to the principle, unpenttrium should have an electronic configuration of 8s25g186f147d1 and filling the 5g-subshell should be stopped at element 138.
Menurut prinsipnya, unpenttrium harus memiliki konfigurasi elektronik 8s25g186f147d1 dan pengisian subkelopak 5g harus dihentikan pada unsur 138.