HOW would the composition of an atom change if both the atomic number and mass number each increase by one?

If both the atomic number and mass number of an atom increase by one, the atom becomes a new element. The atomic number increase indicates that there is one more proton in the nucleus, resulting in a different element on the Periodic Table. The mass number increase reflects the addition of one neutron along with the new proton, which alters the isotope of the element. Overall, the atom transforms into a heavier isotope of the next element in the periodic sequence.