Nobelium-259 has a half-life of 3500 s - AQA - A-Level Physics - Question 28 - 2017 - Paper 2

To find the decay constant ( $\lambda$ ) from the half-life ( t_{1/2} ), we use the formula:

$$\lambda = \frac{\ln(2)}{t_{1/2}}$$

Given that the half-life of Nobelium-259 is 3500 s, we can substitute this value into the formula:

$$\lambda = \frac{\ln(2)}{3500}$$

Calculating this gives:

$$\lambda \approx 1.98 \times 10^{-4} \text{s}^{-1}$$

This value rounds to approximately 2.0 × 10⁻⁴ s⁻¹, which corresponds to the answer choice B.