A modern fifth grader could probably name most of the planets in our solar system.

Elements/The Periodic table of Elements: even in 1864 we only knew about some 44 elements, and the table as we knew it today was still in development. Not that a fifth grader would know them all, but even elemental aluminum was completely unknown until 1825.

In addition, basic familiarity with atomic structure, even an incorrect model, like the one with the looping electrons, wouldn't be developed for over one hundred years.