I took this actual activity from 3 different sources. One was set for a demonstration, two were set for kids to do - one had one step and one had 2 steps.
To extend what was there, I took what was just the activity and changed into a hands on with questions and a map added to it and put it in student friendly written instructions instead of verbal instructions.
I am using this in an environmental science class that has freshmen to seniors. It is a very simple and cheap activity that really illustrates the concept.
It is in MS WORD so it can easily be edited or adapted to your classroom.
There is no key because the answers are truly based on the lab and their reflections. There are some correct answers, but there is no STANDARD answer for every question. There are point values for each question on it. These can be changed very easily if you are interested in different point distribution.