Classify the following nuclides as stable or radioactive:
A) Nickel-63
B) Iron-56
C) Cobalt-59
D) Sulfur-32
E) Iodine-129

• A. Radioactive; Stable; Stable; Radioactive; Radioactive
• B. Radioactive; Stable; Stable; Stable; Radioactive
• C. Radioactive; Stable; Stable; Stable; Stable
• D. Stable; Stable; Radioactive; Stable; Radioactive

Answer: (B)