What is the formula for the period of oscillation of a mass-spring system? 2. Calculate the number of atoms in a sample of plutonium-239.

1. The period of oscillation of a mass-spring system is given by the formula $T = 2\pi \sqrt{\frac{m}{k}}$, where $m$ is the mass and $k$ is the spring constant.

The correct option is A.

2.

• Given: Mass of plutonium-239 ($m$) = $2.00 \text{ mg} = 2.00 \times 10^{-3} \text{ g}$
• Given: Activity ($A$) = $4.59 \times 10^6 \text{ Bq}$
• Molar mass of Pu-239 $\approx 239