The following four junior high school science teachers are teaching the concept "molecule" to their students. In each classroom, some of the students have acquired formal operational reasoning abilities, whereas others think in a concrete operational manner. In which classroom are the concrete operational students most likely to have difficulty understanding?

The Concrete Operational Manner classroom is gonna have difficulty.

Explanation:

This is the answer because Concrete Operational Manner is related to the appropriate use of logic, but it doesn't involved abstracts thinking, logical thoughts and deductive reasoning, this stage of thinking doesn't involved these three elements at once.

So to understand the concept of molecules you need to abstract its definition to understand it, because you can't see a molecules directly in your hand, and then through logical and deductive reasoning, developed the concept for yourself.