A Framework for K-12 Science Education: Practices, Crosscutting Concepts, and Core Ideas was just released.
One of my few frustrations with teaching science at the high school level are the misconceptions kids carry up from lower grades, or from life in general.
I spend a lot of time on misconceptionectomies, but they are resistant to quick cure, particularly if reinforced in the younger grades.
It's OK to teach incomplete science in 2nd grade--it's incomplete even at the highest levels of formal education. Science will always be incomplete, a big part of its appeal. It's plain wrong, though, to teach bad science.
So I am heartened to see this:
"Clearly, incorrect beliefs—such as the perception that food or fuel is a form of energy—would lead to elementary grade students’ misunderstanding of the nature of energy. Hence, although the necessity for food or fuel can be discussed, the language of energy needs to be used with care so as not to further establish such misconceptions."
If you teach science, go get this--it's free, and it will affect your classroom in the years to come.