Tuesday, April 24, 2012

Post Earth Day Fun

With Earth Day just behind us you might want to take the time to create a little biosphere in your own home.    
There are a number of approaches to building an indoor plant enclosure and we have even tried a few here at Cardin (bio-domes in two liter bottles).

My personal favorite, however, are terrariums.  You can buy them pre-made at home centers or gardening stores but it is much more fun to make your own.  Here are two really great “instructables” that I’ve found to get you through the process.


Good luck!

Dean Whitfield
Mathematics and Science Department Chair

Thursday, April 19, 2012

Chemistry and Controlled Explosions


The Cardin chemistry classes are learning about chemical reactions. This is by far the favorite unit of the year. The students love to try different reactions and getting to see some controlled explosions. In class we have discussed the five types of reactions and looked at an example of each type. In synthesis reactions two or more substances react to produce a single product (A+B -> AB). In combustion reactions oxygen reacts with a substance (usually a hydrocarbon) to release energy in the form of heat and light. In a decomposition reaction a single compound breaks down into two or more elements or new compounds (AB-> A+B). A single replacement reaction involves the exchange of a metal or halogen for another element with a lower reactivity (A + BX-> AX+ B). Finally, double replacement reactions involve two anion-cation exchanges (AX + BY -> AY + BX). See if you can identify the following reactions as synthesis, combustion, decomposition, single replacement, or double replacement:

       Ti + 2Cl2 =TiCl4
       AgNO3 + LiI = AgI +LiNO3
       3Mg + 2Cr(NO3)3 = 3Mg(NO3)2 + 2Cr
       2C2H2 + 5O2= 4CO2 + 2H2O
       2H2O2 = 2H20 + O2

Answers:
-Synthesis
-Double Replacement
-Single Replacement
-Combustion
-Decomposition


~Ms. Alexandra Sloane
Science Instructor