Freezing & Melting Point Lab

The last two weeks we've been working on being able to measure and observe physical properties like density and solubility.  The most recent pysical properties we measured were the freezing point and melting points of napthalene, the active ingredient in moth balls.

Freezing point is the temperature that a liquid becomes a solid, where an object's melting point is the temperature where a solid becomes a liquid.  Students were able to relate this unknown chemicals to the freezing & melting points of water, a substance much more well known.

Solubility Lab

We have just completed a short lab focusing on what factors affect the solubility (the ability of a substance to dissolve in another substance) of copper sulfate.  We tested the following factors in class:  copper sulfate in powder or crystal form, type of solvent (water or ethyl alcohol), temperature of solvent, and amount of solvent. 

Density Lab

This week we've been focusing on the physical property of density.  The density of an object can be calculated after the mass and the volume of that object has been measured.  Density is a measure of how tightly matter is packed into a given volume.  To calculate density, students need to find the mass of an object (in grams) and divide that by the objects volume (in either mL or cubic centimeters).  For reference, objects with densities over 1.0 g/mL will sink in water, which objects with densities less than 1.0 g/mL will float in water.  Objects with higher densities will have a tendency to sink while objects with lower densities will tend to rise.

Density is one of the key concepts of 8th grade Earth Science.  It is an essential to understanding many of our topics later this year, including, but not limited to:  rocks/minerals, weather systems (high/low pressure, land/sea breezes, etc.), planetary research, and plate tectonics.

Contour Lines and Topographical Maps

We've spent the last two days working outside (what a great two days of weather too) learning about contour lines.  Contour lines are lines on a topographical map that connect points of the same elevation.  Using a simple hand level and a six-foot rod that has been measured into one foot increments, students developed ways to create a contour line based on a specific elevation.

First Day of School - Observations

The first day of school is completed.  The goal today was to practice making observations, in particular making those observations to be more in-depth, as opposed to a more simplistic version.  Students worked to use their five senses to notice a particular object.  Questions?  As always, let me know!