Thursday, January 26, 2012

Cartesian Diver Lab

beacon news article

7th graders Abby Wells and Kamryn Kingery make Cartesian Divers with the help of  Macy Winkler and Hannah Dougherty.
Chem Club member Allie Melton is excited!

Recently, Mrs. Lau’s 7th grade Science classes visited the Chemistry Lab at PCHS where Mrs. Block and her Chemistry Club helped them create several Cartesian divers.  These divers must sink and rise in a closed bottle of water by changing the density and altering the buoyancy.  Students raced their divers with others to choose a representative for their hour and race to be the best of all three classes!!! 

Representing 1st hour was :   Clayton Floyd with a close second going to Henry Arp
Representing 3rd hour was :  Jenna Lawson
Representing 4th hour was :  Alayna Moore

 The fastest diver went to:  CLAYTON FLOYD!!!!!!
Clayton Floyd had the fastest diver!

          Whether an object floats or sinks in a fluid depends on whether that object’s density is less than or greater than the density of the fluid.  If you add to the mass without changing its volume, a Cartesian diver’s density will increase and it will sink.  You can also increase the density of an object by keeping the mass constant while you decrease the object’s volume.

Boyle’s Gas Law states that as the pressure on a gas sample is increased, it gets compressed into a proportionately smaller volume.  Gas is easily compressed, whereas liquids and solids are not.  When the 2L bottle is squeezed, it compresses the air in the diver and water enters the empty space, increasing the density so that the diver sinks.  When you release the 2L bottle, the air in the diver expands and pushes out the water, changing the density of the diver again.

Thanks to Chemistry Club members for being Champions of Science: 

Hannah Dougherty, Alicia Robertson, Matt Wells, Allie Melton, Sabrina Cooley, Macy Winkler, Thomas Wells, Jessica Rice, Alexis Fiscus, Cody Christenberry, Emily Bierly, Whittney Forster, Austin Gahimer, Damon Daugherty, and  Rebecca Sexton.

Tuesday, January 24, 2012


Haleigh Marshall finds the distance between tracks on a CD!!

First find the diffraction distances!!

It takes a steady hand!!!

Chemistry I students calculated the distance between tracks on a CD using a red laser and a CD to find a diffraction pattern on a wall.  They then used a mathematical formula to discover there are 1500 nanometers separating the tracks on a CD!!  Students also learned that there are a billion nanometers in a meter and that blue lasers can cut through a CD.  Lasers have many uses in the medical and military fields as well as in grocery bar code scanners.

Strongest solar storm since 2005 hitting Earth!!!

By SETH BORENSTEIN more on the solar flare...
AP Science Writer

WASHINGTON (AP) - The sun is bombarding Earth with radiation from the biggest solar storm in more than six years with more to come from the fast-moving eruption.

The solar flare occurred at about 11 p.m. EST Sunday and will hit Earth with three different effects at three different times. The biggest issue is radiation, according to the National Oceanic and Atmospheric Administration's Space Weather Prediction Center in Colorado.

The radiation is mostly a concern for satellite disruptions and astronauts in space. It can cause communication problems for polar-traveling airplanes, said space weather center physicist Doug Biesecker.

Radiation from Sunday's flare arrived at Earth an hour later and will likely continue through Wednesday. Levels are considered strong but other storms have been more severe. There are two higher levels of radiation on NOAA's storm scale - severe and extreme - Biesecker said. Still, this storm is the strongest for radiation since May 2005.

The radiation - in the form of protons - came flying out of the sun at 93 million miles per hour.

"The whole volume of space between here and Jupiter is just filled with protons and you just don't get rid of them like that," Biesecker said. That's why the effects will stick around for a couple days.


ScienceDaily (Jan. 18, 2012) — By shining infrared light on specially designed, gold-filled silicon wafers, scientists at The Methodist Hospital Research Institute have successfully targeted and burned breast cancer cells. If the technology is shown to work in human clinical trials, it could provide patients a non-invasive alternative to surgical ablation, and could be used in conjunction with traditional cancer treatments, such as chemotherapy, to make those treatments more effective.