Question

Cobalt-57 is radioactive, emitting β-particles. The half life for this is 270 days. If 100 mg of this is kept in an ' open container the mass of Cobalt - 57 after 540 days will be

• A. 50 mg
• B. $(\frac{50}{\sqrt2})$mg
• C. 25 mg
• D. Zero

Answer 1

Answer: (C)

25 mg

Answer 2

The correct option is (C) : 25 mg