What causes Uranium to be radioactive?

Answer 1

The stability depend on the ratio between protons and neutrons; uranium has too many neutrons.

Answer 2

Uranium is radioactive because it is an unstable element with a nucleus that can undergo radioactive decay. During this decay process, uranium releases energy in the form of alpha, beta, or gamma radiation as it transforms into other elements over time. This radioactive decay is what makes uranium useful for nuclear energy and weapons.

Answer 3

Uranium is a heavy chemical element; this type of elements are unstable and generally radioactive.