I have just returned from volunteering with Scientist in the Schools, in my son's grade three classroom.
I'm not sure that one day a term is really a way to make kids excited about science, though the leader assured me that as long as the teacher continues with the themes, the kids learn scientific concepts throughout the term.
Well, that's a big if in a French Immersion classroom with a lot of kids, chaos, and other curriculum necessities on the list. I'm not so sure that kids are learning too much science in elementary schools. So science concepts sort of all into the we do at home bag. One thing that a primary teacher once told me is that the kids who bake with their parents regularly are farther ahead in math and science when they arrive at primary school.