Answer:
0.92 μC
Explanation:
In a parallel-plate capacitor, the electric field formed is equal to the charge density divited by the vacuum permisivity e0, as there are no dielectric between the plates. e0 is equal to 8.85*10^-12 C^2/Nm^2. The charge density is the total charge of each individual plate divided by its area. Then, the maximum charge allowed will be equal to:

or 0.92 μC
I hope I'm not too late.
GPE = mass * gravity * height
GPE = 2 kg * 9.8 m/s * 10
GPE = 196 Joules
In the 1930s James Chadwick added the neutrons to the atomic model.
It would mostly be on their website.