Krypton-92 is a radioactive isotope of krypton. Its atomic mass is approximately 91.926154 u.

Here's why:

* Atomic mass is the mass of an atom, usually expressed in atomic mass units (u).

* Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons.

* Krypton-92 specifically refers to the isotope of krypton with 36 protons and 56 neutrons.

Keep in mind that the atomic mass of an isotope is not a whole number because it takes into account the mass of protons, neutrons, and the binding energy of the nucleus.