Bitul

Can I rely on bitul if I drop an apple or fork on the floor in my home?

Shalom U'vracha, Theoretically speaking, if there would have been real chametz that would have gotten stuck to the apple or fork, upon dropping to the floor, then the bitul (nullification of chametz) would not even help. One simply cannot eat chametz on Pesach even if one said the 'bitul'. However, you need not worry because I'm sure that there is no chametz on your floor. You probably washed your floor before Pesach and all the crumbs were cleaned up. Even if some chametz remained on the floor, it probably was not worthy for a dog to eat it before Pesach and therefore is not considered chametz. In conclusion, feel comfortable if your fork falls on the floor and enjoy the chag of Pesach. All the best!