Let's break down the process of beta decay in order to determine the main product when Uranium-235 ([tex]${}_{92}^{235} U$[/tex]) undergoes beta decay.
1. Understanding Beta Decay:
- In beta decay, a neutron in the nucleus of an atom is converted into a proton, an electron (also known as a beta particle), and an antineutrino.
- The overall effect is that the atomic number of the element increases by 1, while the mass number remains the same.
2. Applying Beta Decay to Uranium-235:
- Uranium-235 has an atomic number of 92, which means it contains 92 protons in its nucleus.
- After undergoing beta decay, one of the neutrons in the Uranium-235 nucleus is converted into a proton. This increases the atomic number by 1.
- Therefore, the atomic number becomes 93 (since 92 + 1 = 93).
- The mass number, however, remains unchanged at 235, because the mass number is the sum of protons and neutrons, and the conversion of a neutron to a proton does not change this sum.
3. Identifying the Element:
- An element with an atomic number of 93 is Neptunium (symbol Np).
- Thus, the resulting nuclide after Uranium-235 undergoes beta decay is Neptunium-235 ([tex]${ }_{93}^{235} \mathrm{Np}$[/tex]).
4. Choosing the Correct Answer:
- Among the given options, the one that corresponds to Neptunium-235 is `[tex]${ }_{93}^{235} \mathrm{Np}$[/tex]`.
So, the main product when [tex]${ }_{92}^{235} U$[/tex] undergoes beta decay is:
[tex]${ }_{93}^{235} \mathrm{Np}$[/tex].
