Ochiobi,+Julia

Motion Detectors Bob Becker.

Three things that I already knew were: 1) The human eye is like a photo sensor. 2) A German Physicist named Heinrich Hertz is who the unit for light frequency is named after. 3)" Particles" of light are known as photons. Three things I didn't know were: 1) Anything that senses light is a photo sensor and it depends on the light's capacity for pushing around electrons. 2) Photo sensors rely on light's ability to initiate an electric current. 3) When the light of sufficient energy is shined on a given surface, it causes electrons to be ejected and since different materials have different thresholds, sensors can be made for almost any type of light.

Julia, I wonder what the range of detection is. Is there some threshold that can't be detected? 5 stars. mw

Helium Balloons Sulfur Hexafluoride Bob Becker

3 Things I already knew were that there was a gas that performed the opposite effects of helium, people used balloons to inhale this gas so as to make their voices deeper, and that it can be very hazardous. One thing that I didn't know was that the name of the gas was Sulfur hexafluoride. I also didn't know that instruments used to store this gas might include oils in the valves and regulators or toxic hydrogen fluoride gas. The gas also does not provide oxygen, which our body depends on to live. This article helped to explain the background information on this unfamiliar gas. Julia, OK. Good stuff. 5 *'s MW

Dust Explosion Jeff Johnson

Im still not exactly understanding how substances like sugar and dust can cause massive explosions. That just doesn't seem right.I think that all the factories and plants should be mandated to keep their areas as free of dust as possible. I also think that preventive measures for this sort of problem will probably be very difficult. How can you prevent dust from gathering in large areas. This is something that I feel will continue to be a problem for years to come. Im not really sure how this relates to stoichiometry. I understand how the really small particles of dust are able to mix with the oxygen in the air and any little spark can ignite the particle causing an explosion. Is this an example of stoichiometry?

Julia, The regulations are becoming more strict against accumulating dust - in part because of this tragedy! 5 stars! MW

Mole day

First off, I think they named the mole after Avogaro, because he sort of looks like a mole. His law states that at a fixed temperature and pressure, equal volumes of gases contain the same number of molecules. I also think that he should have been taking seriously during his lifetime. His work was recognized almost 50 years later. The mole was used to solve problems in chemistry two years after his death. His colleague showed the world how to us the mole. Although he received credit for his findings, I still don't think it was fair for his findings to be recognized after his death. What good is praise and recognition, if your not there to enjoy it.

Julia, Thanks for the laugh! Your voice really comes through in your writing. 5 molificent stars! MW

Where do elements come from? Carolyn Ruth

In 1054, Chinese astronomers recorded what they called a guest star in the constalletion of Taurus. We now know that the Chinese and Anasazi witnessed a star explosion, called a supernova. Most of the first 26 elements in the periodic table were inside the star. When it exploded they were released and chemicals combined with each other forming ions and molecules. How is it that the chemicals didn't combine inside the star itself? The Iron nucleus is said to be the most stable nucleus in nature. It resists combing with heavier nuclei. What causes it not to be able to combine with other substances? Julia, Great questions! Not sure we know all the answers! 5 stars! MW

Connecting Element Names with the Names of U.S. Towns Nicholas C. Thomas

Many different towns in the US have strange names. Chemical terms are well represented with many towns named after minerals, elements, or various chemical concepts. They are used to name towns, cities, lakes, rivers, etc. Towns names usually arrive from the regional metal and/ or metal deposits. If somebody wanted to research these various places, they could look up the Standard Road Atlas Index. For more information, they could also look up the local museums, historical societies, and also use the U.S. Board on Geographic Names Website. Some names include: Alloy,WV; Crystal, ND; Ozone, AR; Silica, MN; Gasoline, Texas

Distillation of Crude Oil

Crude oil is made up of various hydrocarbons, which are made up of hydrogen and carbon. Different hydrocarbons run off at different times and temperatures. The ones that require higher temperatures are at the top and the ones that require lower ones are at the bottom. Crude oil is broken up into different things to make different things such as gasoline, polyester, and asphalt

Julia, OK. Good thoughts but a bit short. 63 words. 4 stars. MW

Redefining the Kilogram

The kilogram is the last of all the SI base units that is still defined by a physical artifact. It is equal to the mass of a golf ball sized cylinder of platinum- iridium alloy. Its so small but was ratified the official kilogram in 1889. The prototype is not immutable. It lost 50 ug over time. Some believe that its not good for it to drift because could cause uncertainty in other SI unit that are based on them. The Kilogram is still very important today.

Julia, OK. 5 stars. Connections to our learning? MW