Activity 5: Density

Activity 5: Density



One of the most common attributes of chemical materials that we observe and feel on a daily basis is the density of materials. One of the things we notice in the structures of atoms, is that the atom is mostly space, with a small heavy nucleus and very light electrons orbiting the nucleus. So, how heavy something feels is related to how many protons and neutrons are in the nucleus of atoms that make up molecules. For example, aluminum is much lighter than iron. The "heaviness" of a material is quantified through a characteristic called density.

For this activity, and future ones, we will introduce the usage of simulations and gaming to aid in our understanding of chemical principles. The simulation package we will utilize can be found at this site:

http://phet.colorado.edu/

There are many of this types of things being developed on the web, I have found this one to be excellent for many reasons.

1. It is free! This is an activity supported by the National Science Foundation and many others to aid students and educators.

2. I find the interface to be easy and good for entry level science students and even advanced students. I have found that my 2nd grade son can use these simulations.

3. The science principles covered are very good, and the simulations are quite "real."

4. There is a developing support community for these simulations. For example there is a section for teachers in which there are pre-developed activities and a way to share your own activities.

For future educators and parents, I encourage you to encourage your future school districts to utilize these types of simulations in science education. Students tend to become engaged, and it can alleviate some of the costs and struggles of doing actual experiments in the classroom.



To complete Activity 5, complete the tasks below:

1. Run the Build an Atom simulation http://phet.colorado.edu/en/simulation/build-an-atom and build a neutral lithium atom and a neutral boron atom. Take a picture, or a screen shot, of these two atoms and place them on your blog. List the number of protons, neutrons and electrons for each. Also look up and post the density for each of the elements on your blog.

2. Define density and the equation for density and post on your blog.

3. Run the Density simulation http://phet.colorado.edu/en/simulation/density and complete one(your choice) of the prepared Teaching Ideas and post your results on your blog. The activity you choose should be one of the student intended activities.

4. Complete the Mystery Blocks activity on the Density simulation. Post on your blog the data you collected (mass, volume, and density) and the identification of the material and the known density.

5. Identify and post on your blog the Science Standards that could be met through these activities completed in Activity 5