
One experiment that has fascinated me ever since I saw it, was the separation of hydrogen and oxygen (electrolysis of water). It was done by the teacher my freshman year in high school because it was considered 'dangerous'. It wasn't dangerous, it was inspiring. I didn't learn testing procedure or how to list my observations correctly, what I learned was how to extract hydrogen and it stuck with me ever since. I agree that process and procedure is important to learn but they should be learned with experiments. Experiments are done because the end result is unknown and if that's what you are trying to do then you need to listen to everything Ted has mentioned above. If you are not testing for the unknown but instead demonstrating the awesome power of science then maybe a different approach should be considered. Seems like these postings were related to younger kids in elementary school. Kids in elementary school don't give a rats a** about proper procedure, they want to see cool things happen. Teachers should be spending their time and efforts trying to capture young minds and teach them science. Science has been around for a long time. There's no need to continuously derive how F=ma -- Newton did it a long time ago and it makes sense. Lets go with it. There's plenty of time to teach kids proper procedure in high school and college when their minds are more capable of handling dull subjects.
Here's my opinion for demonstrating the effects of acid. This should be done by an adult, an adult that knows what they are doing, or is at least capable of knowing how to handle when it goes bad. Take a tub of hydrochloric acid and put some steel in it and let the kids witness the power demonstrated by the acid on the wheel. Unfortunately I know for a fact, it's not a joking matter. I could have sent smoke signals with the reaction I had going on.
Go big or go home. Nobody cares how lemon juice changes the color of a penny, nor will the kid remember it 15 years later when he's dumping wheels into hydrochloric acid. Teach these kids real science. If you don't know science, but are instead hunting for answers on a website, then maybe you should do some learning before teaching today's youth. My best teacher in high school wasn't a teacher, he was a scientist. Luckily he knew how to communicate his knowledge in an acceptable manner. But let's also face the fact that some dogs just won't hunt. In other words, some kids aren't going to care no matter what.
- Wilmington, North Carolina, USA