An inquiry-based activity I would use would be on the topic of the solar system. I would use the solar system song as an initial introduction to the eight planets in the solar system. This song gives three to four facts about each planet and displays them in the correct order from the sun and their size comparable to one another and the sun.
Each group/child would be given a blank planet made out of paper mache and asked to paint it the colour of the planet that their group has been assigned.
While the planets are drying the children would be encouraged to use books/iPads to research some facts about their planet.
When the planets are dry each group would present their planet and facts about their planet to the whole class