Gerberick,+Rachel

I read the article "Mentos and Coke" because I have done this experiment before and wanted to know more about why it happens. Before reading what I already new about this topic was that when you put mentos into coke it would make the coke explode out of the bottle in water fountain formation. I also knew that the coke works best for this if it is diet. The last thing I already knew was that the more mentos you put into the diet coke, the better it will explode and the higher it will spray. After reading this article I learned that the amount of CO2 one can dissolve in a liter of solution depends on the pressure of the CO2 pushing on the solutions surface. Also that it can take several hours of a bottle of soda to go completely flat because the undissolving and bubbling of the CO2 begins right away but is a slow process. The last thing I learned from the article "Mentos in Coke" was that at the bottling companies they make the insides of the soda cans and bottles smooth and free of nucleation sites because if they were rough the soda would spray out the moment the bottle was opened.

Rachel, Very good post!!! You really picked out the main points. 5 stars! MW

Post for Video 9/19/11

One thing that I found interesting was that even something like crude oil can be separated through distillation, and the different parts of the distilled oil can be made into various products we use today. Distillation starts by crude oil being heated and the different substances throughout it moving to various spots in the flask. The substances with the highest boiling point will travel to the bottom of the flask where the Bunsen burner is, which is the main heat source, and the substances with the lowest boiling point will rise near the top because they heated up the fastest. The bunsen burner's temperature gets increasingly colder as you go up the bunsen burner. The liquids inside the flask condense and reach their boiling points at different temperatures, which is how distillation is possible. Rachel, That pretty well sums it up. 5 stars! MW

Post on Motion Detectors 10/4/11

==== Before I had even read this article on motion detectors I already knew a few things. First of all I knew that motion detectors work when you go near them. Whether it be a porch light turning on when you walk past it or an air freshener spraying when you walk into a room, they all work by detecting when a person or thing is near them. Secondly I knew that garage doors have motion detectors and they work with a light source. If that light source gets cut off by a person's foot or a cat it sends a signal to stop the garage door from closing so that nothing is crushed by its force. The last thing I knew before reading this article was that electrons revolve around the nucleus every-which-way and when one of them moves up and then comes back down its energy is given off to a quantum which is then transferred to a photon which creates the waves and color. After reading this article I learned that sensors can be created for just about any type of light because different materials have different thresholds and sensors work when sufficient energy is shined on a specific surface and electrons are ejected, a sensor then relies on light's ability to start an electric current. I also learned that sometimes light behaves like a wave but other times, like in the photoelectric effect, it behaves more like a particle and the energy of it is only depended on frequency not on the intensity, which impacts how many photons there are. The last thing I learned was that there are three methods used with motion detectors (one that uses a light source, one that uses the motion of someone walking near it, and one that uses infrared radiation) and each one is used in a specific situation depending on what is being detected. ====

Rachel, I thought it was interesting to read about the three types of detectors too. Very well-written! 5 huge stars. MW