Atomic Structure An updated version of this lesson is available at Visionlearning: Atomic Theory & Ions & Isotopes In the last lesson we learned that atoms were particles of elements, substances that could not be broken down further. In examining atomic structure though, we have to clarify this statement. Atoms are made up of 3 types of particles , and . A neutron walked into a bar and asked how much for a drink. The bartender replied, "for you, no charge." -Jaime - Internet Chemistry Jokes The atom above, made up of one proton and one electron, is called hydrogen (the abbreviation for hydrogen is H). Keep in mind that atoms are extremely small. While you should keep in mind that electrons actually form clouds around their nucleii, we will continue to represent the electron as a spinning particle to keep things simple. In an electrically neutral atom, the positively charged protons are always balanced by an equal number of negatively charged electrons. As you can see, helium is larger than hydrogen.
Aster - Archives Aster devient Recherches en didactiques des sciences et des technologies à compter de janvier 2010. La revue Aster contribue au développement de la recherche en didactique des sciences et à la diffusion des connaissances qui permettent de mieux comprendre les situations d’enseignement-apprentissage, les contenus d’enseignement et l’organisation des plans d’étude. Elle s’intéresse aux processus d’accès aux savoirs, à la construction de compétences par les élèves et les étudiants, et à la professionnalisation des enseignants et des formateurs, tant dans des situations d'éducation formelle que non formelle. Aster publie des articles utilisant des méthodes variées et des cadres théoriques divers pour étudier ces questions de l'école à l'université et dans la formation des maîtres. La revue Aster est ouverte à des contributions internationales, favorisant ainsi la circulation d’idées dans le champ de la didactique des sciences.
Astronomy Picture of the Day For Students- Stanford Solar Center Activities for Students You cannot teach a man anything, you can only help him to find it for himself. -Galileo Galilei Tour through these topics to find exciting activities, images, interactive tools, text, and other resources to let you research our special star -- the Sun. Check out our new comics series! Design Your Own Solar Cupcakes! Build an SDO Hexaflexagon!
Science News, Articles and Information | Scientific American Persée : Portail de revues en sciences humaines et sociales Titan « Lights in the Dark Illustration of a sunrise above a liquid methane lake on Titan. © Ron Miller. All rights reserved. We’ve known for quite some time now that lakes of liquid methane and ethane exist on the frigid surface of Saturn’s overcast moon Titan. While the sheer presence of large amounts of liquid on another world is fascinating, one thing that’s particularly intrigued scientists about these hydrocarbon lakes is their uncanny stillness — in many radar images they appear to be literally as smooth as glass, with no indication of movement or wave action of any sort. And although liquid methane isn’t water and probably behaves differently, with Titan’s substantial atmosphere it only makes sense that some sort of waves would get kicked up across lakes so vast, even from the most moderate seasonal breezes. Read the rest of this article here. Like this post? Like this: Like Loading...
Speed of the Earth's Rotation The Question (Submitted April 01, 1997) I am trying to find out the speed of the turning of the Earth. The Answer Basic Answer The circumference of the Earth at the equator is 25,000 miles. Multiply by cosine of your latitude to see how fast the Earth is rotating where you are. Earth is also moving around the Sun at about 67,000 miles per hour. Advanced Answer If by "turning" you mean the rotation of the Earth about its axis (where axis just means the straight line between the North and South poles) it is quite easy to figure out how fast any part of the Earth's surface is moving. The Earth rotates once in a few minutes under a day (23 hours 56 minutes 04. 09053 seconds). An object on the Earth's equator will travel once around the Earth's circumference (40,075.036 kilometers) each sidereal day. The Earth is doing a lot more than rotating, although that is certainly the motion we notice most, because day follows night as a result.
5 Really Weird Things About Water Water, good ol' H2O, seems like a pretty simple substance to you and me. But in reality, water - the foundation of life and most common of liquid - is really weird and scientists actually don't completely understand how water works. Here are 5 really weird things about water: 1. Hot Water Freezes Faster Than Cold Water Take two pails of water; fill one with hot water and the other one with cold water, and put them in the freezer. In 1963, a Tanzanian high-school student named Erasto B. Thankfully, Mpemba didn't back down - he convinced a physics professor to conduct an experiment which eventually confirmed his observations: in certain conditions, hot water indeed freezes before cold water*. Actually, Mpemba was in good company. But how do scientists explain this strange phenomenon? 2. Everybody knows that when you cool water to 0 °C (32 °F) it forms ice ... except that in some cases it doesn't! Note: Similarly, superheated water remains liquid even when heated past its boiling point. 3. 4.
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