contestada

The alpha decay of a radioactive nuclide (X) emits a He-4 nucleus and produces an isotope of Superscript 235 subscript 92 upper U.. What is X? Superscript 235 subscript 91 upper P a. Superscript 235 subscript 93 upper N p. Superscript 236 subscript 92 upper U. Superscript 239 subscript 94 upper P u.