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Showing posts from February, 2018
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This video shows an experiment to compare the reactivity of three different metals in single replacement reactions with HCl and water.  The ranking of how reactive metals are in single replacement reactions is called the activity series. I hope this was helpful!

Shielding Radiation

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This video shows footage of a rock being tested for emission of radiation. Three different materials are tested to determine their effectiveness in shielding radiation. The three materials are; paper, a wooden block and sheets of lead.

How do we know the universe is getting bigger?

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To understand the evidence that the universe is getting larger, we need to understand the Doppler effect.  This is the reason why a siren from a police car or fire truck has a higher pitch as it is approaching and a lower pitch when it is traveling away from us. The two images below are really useful in trying to better understand the Doppler effect. The first image has a stationary red dot which is giving off waves, which is shown by the concentric blue circles.  The wavelengths of the waves being given off are represented by the distance between the concentric blue circles.  The waves would appear the same to four observers each located at the corners of the square area.  The second image shows waves being produced by a moving object.  In this case, the waves would appear to be different to observers on the right or left side of the square area.  Observers on the left side would observe waves that are stretched out because the object giving off the waves is moving away from

Radioactive Dinner Plate

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This video shows two plates being measured for emission of radiation. The orange Fiesta plate was made using a glaze which contains uranium oxide. Fiesta dinnerware was produced by the Homer Laughlin China Company of West Virginia. Prior to World War II the glazes used natural uranium.  This practice stopped during the war when the US government seized the company's stock of uranium for the Manhattan Project.  In the late 1950's the Atomic Energy Commission relaxed restrictions on uranium and production practices switched to using depleted uranium to produce the red-orange glaze. The US Environmental Protection Agency recommends that dinnerware produced with uranium glaze should not be used for food, drink or food storage.