A radioactive nuclide X decays into nuclide Y. The decay constant is \(\lambda\). The initial number of nuclei of X is \(N₀\). How many nuclei of X remain after a time \(t\)?

• A

  \(N₀ / (\lambda t)\)

• B

  \(N₀ (1 - e^{-\lambda t})\)

• C

  \(N₀ e^{-\lambda t}\)

• D

  \(N₀ / 2\)