1. All students can be involved as they do no need to find an answer only a question and you could expand this in a variety of different ways: Students could write their answers on a post-it which could then be collected and stuck on to a question wall and revisited throughout or at the end of the lesson to see how many have been answered or can now be answered by students. Unanswered questions could be set for homework or carried over to the next lesson.
Students could swap questions and challenge their partner to come up with a logical or valid answer.
This activity could act as a starting point for students to think about how to ask good questions. Some ideas for further discussion on this topic can be found on a PowerPoint slide here.