Science demonstrations can be covered under the following terms.
It assumes that you are demonstrating only and not running a science workshop with the group, as this cannot be covered.
What you would need to do is select the activities that form part of your performance. You would need to select Actor/Theatre Performer/Theatre in Education performer and if you are using any flame or liquid nitrogen etc, select Fire in Category 3. You can also select any other activities that you do.
So, the first test would be: Are you demonstrating? Or are the kids doing the activities with you? If they are, we cannot cover this.