This is the second Examiner challenge question aimed at stretching you to achieve level 7-9 in science. Some of you are opting in to these challenges and doing the questions online as Microsoft Quizzes. When you have, these have been marked and the question and mark scheme has been sent to you, along with this Podcast. Here it is for everyone to listen to. Hopefully it will be useful, although it is even better if you have a go at the question first. At the moment I am sending these out as flexible tasks in Show My Homework so look out for them. They go out on a Monday and I mark them on and produce the Podcasts on Saturday morning.