Monday, June 25, 2012

Worldviews Used In Teaching Homeschool Science

Worldviews are the ways in which science facts are framed when they are taught. The most common worldviews are those of Creationism and Materialism and some may include Darwinism and Intelligent Design. These are opposing models, diametrically disparate with strong proponents on each side of the fence. So is it possible to teach homeschool science in a way that honors both types of framework? Actually there is - and here's why it's important to make your child aware of them all.

The Different Worldviews

In a very basic manner, all worldviews used to frame homeschool science teaching fall into one of two categories: theological (Creationism) or materialistic (Darwinism).

The Creationistic worldview defines all things in science as God's creations. Since God created everything in the world, the student only learns the concepts of science that fit into that particular framework.

Thursday, June 14, 2012

How to Collect Forensic Science Fingerprints Using Latent Print Powders at the Crime Scene

Latent Fingerprint development has challenged crime scene investigators for decades. Collecting forensic science fingerprints has evolved from the early use of lampblack (soot) to complex formulations that incorporate some sophisticated chemistry. This article will examine the use of latent fingerprint powders-included will be the whys and wherefores of latent powder formulations.

Latent print powders are divided among several different categories-each category having very specific uses. The first consideration for the crime scene investigator to examine is the type of surface expected to yield latent prints:

Porous Surfaces: This includes paper, cardboard and raw wood. Unless latent prints are suspected to be reasonably fresh, latent print powders are not of much use on non-porous surfaces, since the moisture content disperses into the substrate and ridge detail is lost.

Non-Porous Surfaces: This is where latent powders most often come into play. The problem is, however, that all non-porous surfaces have different characteristics that require a specific formula of latent powder.

Saturday, June 2, 2012

How to Calculate the Molarity of a Solution

Concentration has many units but the most commonly employed unit is Molarity. It is defined as the total number of moles of a solute that are dissolved in a liter of a solution. The method for calculating molarity is not so difficult rather it is a quite easy task and little practice can make you an expert in it.

The most important thing for calculating molarity can be derived simply by the unit of molarity i.e. moles of solute in addition to the liters of solution.

A very trouble-free example is given here which is solved with a very easy method and it covers almost all the steps that a molarity problem can suffer from:

Question: 10 grams of NaHCO3 are sufficient to make a saturated solution containing the volume of 500 milli-liters. Calculate molarity of this solution?

Solution:

If we closely observe this example, then it does not contain either of the parameters that are written in the formula of molarity i.e. moles of solute and liters of solution. But here weight of solute is given in grams and volume of solution is given in milli-liters.