Understanding Atomic Weight
The atomic weight of an element is determined by the mass of its protons, neutrons, and electrons. For carbon-12 (6 C12), the atomic weight is primarily derived from its nucleus, which contains 6 protons and 6 neutrons.
Mass Adjustments
- Electron Mass: The mass of the electron is stated to be 2 times the original value. In atomic weight calculations, the mass of electrons is negligible compared to protons and neutrons, so this change will have minimal impact.
- Proton Mass: The mass of the proton is reduced to 1/4 of its original value. This significant reduction will have a direct effect on the atomic weight.
- Neutron Mass: The mass of the neutron is 3/2 times its original value, leading to an increase in the contribution of neutrons to the atomic weight.
Calculating Change in Atomic Weight
1. Original Proton Mass: Let the original mass of a proton be P.
- New mass of a proton = P/4.
2. Original Neutron Mass: Let the original mass of a neutron be N.
- New mass of a neutron = (3/2)N.
3. Original Atomic Weight of C12:
- Atomic weight = 6P + 6N.
4. New Atomic Weight:
- New atomic weight = 6(P/4) + 6(3/2)N = (3/2)P + 9N.
5. Change in Atomic Weight:
- Change = New atomic weight - Original atomic weight.
- This results in a notable decrease in weight due to the reduced mass of protons, while the increase due to neutrons partially offsets this.
Conclusion
In summary, the atomic weight of carbon-12 will decrease significantly due to the drastic reduction in proton mass, even though the neutron mass increases. This intricate balance will ultimately alter the atomic weight, demonstrating how mass changes in subatomic particles can significantly influence elemental properties.

Decrease by 12.5 %