Was Crocodile stronger at Marineford? Or was he holding back in Alabasta?

 During the Alabasta arc, Crocodile displayed a level of power that was initially considered overwhelming by the Straw Hat Pirates. He possessed the Logia-type Devil Fruit called the Suna Suna no Mi (Sand-Sand Fruit), which granted him the ability to control and transform into sand. He had a reputation as a Shichibukai and controlled the desert kingdom of Alabasta from the shadows. His strength was showcased through his battles with Luffy and others. At Marineford, Crocodile was present as part of the war that took place at Marine Headquarters. While he did participate in the battle, he didn't display the same level of dominance as some other powerful characters present. This has led fans to speculate that he might not have been as strong as initially portrayed in Alabasta. It's important to note that power scaling and character abilities can be subject to interpretation and development by the author. Oda often keeps details deliberately open-ended to keep the story intriguing.

Why are protons bigger in size as compared to electrons?

 Protons are larger in size than electrons because they have a much greater mass. The mass of a proton is about 1,800 times greater than the mass of an electron.

The size of an atomic particle is determined by its mass and the strength of the forces that hold it together. In the case of protons, the strong nuclear force holds the protons and neutrons together in the nucleus of an atom, and this force is much stronger than the electromagnetic force that holds electrons in orbit around the nucleus. As a result, protons are able to hold themselves together more tightly, and this results in their larger size.

It is important to note that the size of an atomic particle is not a fixed property, and the size of a proton or an electron can change depending on its environment. For example, the size of a proton can change when it is bound inside the nucleus of an atom, due to the influence of the other protons and neutrons. Similarly, the size of an electron can change when it is in an excited state, or when it is subjected to strong electromagnetic fields.