Give the sequence of planning for your science classroom using inquiry approach in teaching concept of density.
a. allow students to determine relationship between objects that float and sink.
b. allow students to play with water in a tub with different objects.
c. ask students to design a small boat that can carry 1 kg of weight.

The correct option is b → a → c.

When teaching the concept of density using an inquiry-based approach, the sequence of planning should move from free exploration to structured observation and conceptual understanding, and finally to practical application/engineering design.

Step-by-step breakdown of the sequence:

1. Free Exploration (Step b): Allow students to play with water in a tub with different objects.
Inquiry learning begins with open-ended exploration and engagement. Allowing students to freely interact with water and various objects generates curiosity and gives them concrete experiences before formal concepts are introduced.

2. Guided Inquiry & Concept Formation (Step a): Allow students to determine relationship between objects that float and sink.
After initial exploration, students make structured observations to identify patterns and relationships regarding why certain objects float while others sink, leading them directly to the underlying concept of density.

3. Application & Problem Solving (Step c): Ask students to design a small boat that can carry 1 kg of weight.
Finally, students apply their newly gained conceptual understanding of floating, sinking, and density to a real-world engineering challenge/design task.

Therefore, the logical planning sequence for an inquiry-based lesson on density is b → a → c.