Neptunium (atomic number 93) can decay into plutonium (atomic number 94) through a process called beta decay. Beta decay occurs when a nucleus undergoes a transformation, resulting in the emission of a beta particle.
In the case of neptunium-237 (the most common isotope of neptunium), it undergoes beta decay by emitting an electron (β-) and an antineutrino (ν) to become plutonium-237. The decay process can be represented by the following equation:
Np-237 → Pu-237 + e- + ν
In this equation, the neptunium-237 nucleus (Np-237) transforms into plutonium-237 (Pu-237), and an electron (e-) and an antineutrino (ν) are emitted.
It's important to note that there are other isotopes of neptunium and plutonium, each with different decay modes and half-lives. Neptunium-237 has a relatively long half-life of about 2.14 million years, while plutonium-237 is also a radioactive isotope with a half-life of approximately 45,000 years.
The decay of neptunium-237 into plutonium-237 is a natural radioactive process that occurs over time as the neptunium nucleus undergoes nuclear transformations to reach a more stable configuration.