In a decay sequence, what is the starting element before decay called?

In a decay sequence, what is the starting element before decay called?

• A. Starting element
• B. Initial nucleus
• C. Precursor
• D. Parent material

Answer: (D)

In a decay sequence, the substance that starts the chain is the parent material. It’s the original material that contains the radioactive nuclide before any decay occurs, and it produces the daughter products as the chain progresses. The term emphasizes the source substance rather than a single nucleus, which is why it’s the most fitting description in this context. The other terms are less precise for describing the starting point of a decay sequence.

In a decay sequence, the substance that starts the chain is the parent material. It’s the original material that contains the radioactive nuclide before any decay occurs, and it produces the daughter products as the chain progresses. The term emphasizes the source substance rather than a single nucleus, which is why it’s the most fitting description in this context. The other terms are less precise for describing the starting point of a decay sequence.