Question

how much input of energy is required in order for nuclear decay to happen in an atom?

Explanation:

Step1: Understand nuclear decay nature

Nuclear decay is a spontaneous process.

Step2: Determine energy requirement

No external energy input is needed as the nucleus is in an unstable state and decays to a more stable state on its own.

Answer:

Zero energy input is required for nuclear decay to happen in an atom as it is a spontaneous process.