This post includes a video showing single slit diffraction of a LASER beam. The derivation develps formulas to find the diffraction maxima and minima as a function of angle. Continue reading Diffraction
Monthly Archives: March 2016
Biology Review for CST/NCLB 2016
Science Geek Biology Practice Quiz
Science Geek Biology Power Points
Attention all students: if you’re working from a school computer, you should open the HTML5 version of the Power Point presentations
Polarization
Polarization of light causes sun-glare off roadways. Polarized sunglass lenses help remove this glare Continue reading Polarization
The Arrhenius model of acids and bases.
There are three theories of acids and bases. These are Arrhenius, Bronsted – Lowry, and Lewis, each named for the person (people) who developed the theory.
You can think of representing these theories in a Venn Diagram composed of 3 concentric circles. The innermost circle is the Arrhenius theory which was the first of the three theories and explains the behavior of a special class of acids and bases. The next larger circle, containing the Arrhenius circle, is the Bronsted-Lowry theory which is larger because it explains the behavior of a much larger class of chemicals. Finally, the outer circle is the Lewis theory which explains the acid and base properties of all chemicals and encompasses the other two theories.
In 1886, a Swedish chemist named Svante Arrhenius proposed the idea that an acid is a chemical which releases a Hydrogen Ion when it is dissolved in water and a base is a chemical which releses an Hydroxide ion when dissolved in water.
{for an animation of how this works, see also our post on strong and weak acids}
This is a fairly detailed video about Arrhenius acids and bases and slats. Its worth watching but be sure to take notes!
Next comes the Bronsted-Lowry theory
Acids, Bases, pH, pOH and the Math Behind Them
This post covers the math and mystery behind pH, pOH and the equilibrium constant for water. Continue reading Acids, Bases, pH, pOH and the Math Behind Them
Gas Law Simulator
<div style=”position: relative; width: 300px; height: 197px;”><a href=”https://phet.colorado.edu/sims/ideal-gas/gas-properties_en.jnlp” style=”text-decoration: none;”><img src=”https://phet.colorado.edu/sims/ideal-gas/gas-properties-600.png” alt=”Gas Properties” style=”border: none;” width=”300″ height=”197″/><div style=”position: absolute; width: 200px; height: 80px; left: 50px; top: 58px; background-color: #FFF; opacity: 0.6; filter: alpha(opacity = 60);”></div><table style=”position: absolute; width: 200px; height: 80px; left: 50px; top: 58px;”><tr><td style=”text-align: center; color: #000; font-size: 24px; font-family: Arial,sans-serif;”>Click to Run</td></tr></table></a></div>