This is a recipe that is adapted from Earl Lee's watermelon caviar Recipe from Toastable.com (http://toastable.com/2010/08/watermelon-caviar-an-introduction-to-molecular-gastronomy/). It demonstrates a technique used in molecular gastronomy. A polymer, sodium alginate, is mixed in with watermelon juice. The mixture is then carefully inserted, with a syringe, into a solution of calcium chloride. A chemical reaction happens between the calcium chloride and sodium alginate to form calcium alginate. The calcium alginate is not soluble in water and thus forms a gel around the outside of the watermelon juice. The calcium alginate watermelon spheres are edible.
Views: 103041 sciencefix
This video shows 7 different inertia demos. Newton's 1st law of motion (law of inertia) states that objects at rest will remain at rest, and objects moving at constant velocity will remain moving at constant velocity unless acted upon by an outside unbalanced force. Some of these demos show the first part of the law and some demonstrate the second part of the law. Sciencefix.com producer: Darren Fix
Views: 273657 sciencefix
Anything that has mass, has inertia. The broom applies an unbalanced force to the pie tin, causing the pie tin to accelerate. The rim of the pie tin applies an unbalanced force to the egg holder, causing it to accelerate. With no balanced force to counteract gravity, the egg falls into the tennis ball can of water.
Views: 17649 sciencefix
In my class students learn about chemical reactions and also the difference between elements and compounds. Students learn that the 5 signs of a chemical reaction are: 1) color change 2) gas production 3) precipitation 4) temperature change 5) change in properties (smell, texture, taste, density, etc.) Students also learn that compounds are chemicals that have 2 or more elements bonded together, such as water. In this demonstration, students can observe the compound water undergo a chemical reaction, and break apart into hydrogen and oxygen gas. This demonstration can be done on an overhead projector so that all students can view it easily. ScienceFix.com Producer: Darren Fix
Views: 10187 sciencefix
Five demonstrations show inertia in action. Inertia dictates that objects at rest will remain at rest, and objects moving at constant velocity will remain moving at constant velocity, unless and outside unbalanced forces is applied. ScienceFix.com Producer: Darren Fix
Views: 6727 sciencefix
Sodium (Na) is a highly unstable alkali metal. It needs to give up one electron to become stable. When a cubic centimeter sized piece of sodium is placed into water, a vigorous chemical reaction occurs in which sodium hydroxide (NaOH) and hydrogen gas is produced. ScienceFix.com Producer: Darren Fix
Views: 507480 sciencefix
It's that time of year where school is starting and that means teachers have to go over the safety rules in the science classroom. Teachers who teach chemistry must have all of their students wear safety goggles during lab activities. Being a teacher whose middle school students don't really want to wear them, I have a simple demo for students to understand the need to wear them.
Views: 9142 sciencefix
Bio Rad's pGLO transformation kit is demonstrated in this video. The pGLO plasmid has 3 genes spliced into it. Bla is a gene that codes for a protein that nullifies the antibiotic ampicillin. Ara C is a gene that codes for a protein that turns on the GFP gene. The GFP gene codes for the green fluorescence protein (GFP), which glows green in the presence of UV light. The GFP is normally found in the jellyfish Aequorea victoria, which makes it bioluminescent. The pGLO plasmid is inserted into E. coli bacteria, which makes the bacteria survive in ampicillin and glow green in UV light. ScienceFix.com Producer: Darren Fix
Views: 19113 sciencefix
This video shows harvester ants in the AntWorks habitat. The habitat contains a blue gel the ants can tunnel through and also eat. The gel was developed for a space shuttle mission investigating ant behavior in microgravity. Regular ant habitats utilize soil for the ants to tunnels through and live. Unfortunately, soil tunnels would collapse with the violent shaking of a space shuttle lift off. Thus this gel was developed to withstand that. The AntWorks gel is illuminated from the bottom with four LED lights to give the appearance of a blue glow. The video clip shows the harvester ants using their jaws to make tunnels, and their antennae to communicate with each other. ScienceFix.com Producer: Darren Fix
Views: 15258 sciencefix
I decided to try out a demo that I saw Steve Spangler do. I've always wanted to ignite a balloon filled with 2 parts hydrogen gas and 1 part oxygen gas. It just wasn't much of an option in my classroom. The egg is much more practical. Hydrogen gas is produced by reacting zinc metal with hydrochloric acid. The hollowed out egg is filled with the gas and then ignited.
Views: 7276 sciencefix
It's the beginning of the school year and teachers need to go over safety rules. After a chemistry lab or a biology lab involving dissections it is important for students to wash hands to get rid of chemical residues or to prevent the spread of pathogens. The video demonstrates how pathogens and/or chemical residues can spread quite easily and how washing hands is important to prevent it. Glo Germ is the product used in this demonstration.
Views: 157049 sciencefix
The reason the balloon gets pushed into the flask is due to the rapid cooling of the hot gases in the flask once the chemical reaction stops. The gases condense as a result, lowering the pressure inside the flask and the atmospheric pressure pushes the balloon into the flask.
Views: 10290 sciencefix
My students often stare in wonder at the radiometer that sits in the window sil of my classroom. A lot of them think it's the temperature that causes the different spinning rates. Others think it's the amount of light. I decided to attempt to see which factor determines it.
Views: 13262 sciencefix
Discrepant events are the cornerstone of a constructivist science education. A good demo will force a student to confront their preconceived notion of how a phenomena works. Students must work at trying to resolve the conflict between what they just saw and their prior knowledge. Magic tricks are a perfect example of that. Students think what they just saw is magic or they try to figure out how the magic trick works. This is a simple magic trick that involves the scientific concept of friction (and a little bit of tension).
Views: 5393 sciencefix
At the beginning of the school year I like to introduce my 8th graders to think like a scientist. I give students an Ob-Scertainer (http://www.flinnsci.com/store/Scripts/prodView.asp?idproduct=14896 ). It's a great way to discuss what observations, predictions, hypotheses and results are. It also leads to a good discussion of the significance of results. I want to thank the teachers that volunteered to be my "students" for this video.
Views: 2255 sciencefix
There are 12 items of different densities. Will they sink or float based on their masses?
Views: 9231 sciencefix
Students often have misconceptions about certain science concepts. They occur naturally and they do not happen because a student is not intelligent. The human brain tries to fit information in an easy to digest construct, even though it is not accurate. Misconceptions are very difficult to break. The best way for students to break their misconception is to articulate their understanding and then try confront a demo or new piece of information that contradicts that misconception. In the video some teachers are asked the question, "What causes the phases of the moon?" They then are asked to demonstrate their thinking and to explain how it works. An explanation and demonstration of how the phases of the moon actually happen takes place in the last third of the video.
Views: 15168 sciencefix
A while back I posted an item from Steve Spangler's Science site that demonstrated how to make lava lamps. I decided to go ahead and try it and I filmed it. The materials that are required for the demo are shown below. As the video shows the peanut butter jar is filled with 3/4 vegetable oil and 1/4 colored water. Place an 1/8 of an Alka-Seltzer tablet into the jar. The Alka-Seltzer reacts with the water to form carbon dioxide gas bubbles. The gas is less dense than the water or oil. The carbon dioxide gas bubble attach themselves to the colored water, causing them to rise to the surface. When the gas breaks through to the surface the higher density colored water droplets sink back down into the jar. The second part of the video shows the same demonstration, this time in a large test tube. ScienceFix.com producer: Darren Fix
Views: 1394 sciencefix