**11. Appropriate metacognitive challenge level**

Setting the appropriate metacognitive challenge levels for learners enables learners to progress and develop the knowledge of themselves as learners (metacognitive knowledge, tasks, and strategies). The metacognitive challenge level motivates learners in accepting doing the required chemistry learning task. Learners should be motivated for them to accept a chemistry challenge. The

chemistry tasks given to learners should not be above the level of the learners' cognitive level especially when they are expected to use the new learning strategies [4, 9].
