Question

Before the fission process takes place, lead-207 is bombarded with neutrons, it can change into

Answer 1

Lead-208, because I guessed and that was the answer.

Answer 2

Lead-207 can change into Lead-208.

When Lead-207 is bombarded with neutrons, the atom acquires the neutron. Adding a neutron only changes the mass number of the atom. This does not involve change in the identity of the atom. So, Lead-207 can change into Lead-208 without change in its chemical properties.