Tuesday, June 28, 2011
To begin this activity, review the Content Slides in D2L on States of Matter and Intermolecular Forces. We are all familiar with the states of matter (solids, liquids and gases) for many substances. In the First Activity we explored these states of matter for water. In Activity 6, we would like to take our overall understanding of states of matter to the molecular level. We will use the States of Matter simulation at http://phet.colorado.edu/ . There are two key characteristics of molecules that determine their state of matter. The first one is the temperature of the matter, and the second one is the intermolecular forces (how well atoms/molecules stick to one another) between atoms and molecules.
One of the first things to think about here is temperature. Temperature and thermometers have a very similar relation to speed and speedometers. For all practical purposes, a thermometer is really a speedometer for molecular speed or motion. At this site (another good NSF funded science education site) http://www.visionlearning.com/library/module_viewer.php?mid=48 , is a good overview of temperature with a good image of the temperature scales and conversions between different scales. Notice that the Kelvin scale starts at zero and goes up from there. This is like our car speedometer, in that at 0 Kelvin (K), molecular and atomic motions stop. As the temperature rises, atoms and molecules begin to move faster and faster.
The second thing to consider is the intermolecular forces (attractions) that exist between molecules. In the D2L content slides there are a few types of attractions described, notice all of these are defined by the attraction that exists between positive and negative charges. Water is a great example of a molecule that has strong attractions that we call hydrogen bonding. It is this strong attraction that makes water a unique molecule on our planet. It turns out that the hydrogen atoms tend to be positive in charge, and the oxygen atoms tends to be negative in charge.
Tasks to be completed for Acitivity 6
1. Convert 0°F, 32°F, 70°F, and 212°F to Kelvin
2. Complete the Teaching Idea: States of Matter Simulation Lab by Kelly Vaughan. Complete the lab worksheet as if you were a student, and then post this on your blog. You can scan it or just take a picture of it.
3. In the States of Matter simulation, choose the Solid, Liquid, and Gas Tab at the top of the screen. Choose the water molecule and cool the water to 0 K. Describe how the water molecules are aligned and attracted to each other. Which atoms are attracted to which other atoms?
4. Switch to the Phase Changes Tab on the States of Matter simulation. Notice how on the bottom right there is a small red dot that indicates where the system is at as far as temperature, pressure and state of matter. Play with the simulation to notice changes, notice that when you push down the pressure can go way up and explode the box. On your blog, report a temperature and pressure required to make oxygen a liquid. This is sometimes how the oxygen exists in pressurized oxygen tanks, perhaps like ones you may use to go diving.
5. List and describe at least two Science Standards that this activity addresses.
Friday, June 24, 2011
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:
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
Wednesday, June 22, 2011
Activity 4: Exploration of Science Education Standards
CHEM 105 not only provides an opportunity for students to learn more about chemistry and science, but it also offers an opportunity for future educators, parents and members of society to understand the expectations society has created for science education standards. In the last four activities (5-8) we will explore science concepts and also relate these to the science standards we will first explore in Activity 4.
For this activity please refer to the Wisconsin Science Standards at this website:
At this site you will find Standards A- H for grades 4, 8 and 12. Since most of the students in this class are future early childhood educators, I would like for you to focus on the Grade 4 Standards. If you would like, feel free to address the other grade levels if you would like!
To complete Activity 4, choose a sub-standard under each of the Standards A thru H and describe something that you have done either in this class or outside of this class, perhaps in previous classes, that indicates that you have met the sub-standard. Each of these descriptions should be at least a paragraph long.
Here is a link to the sub-standards for Standard A:
Saturday, June 18, 2011
Now that we have some familiarity of atoms, Activity 3 explores how elements come together to make molecules.
In brief, the electrons that surround elements interact in a good way with electrons around other elements to create chemical bonds. These chemical bonds are what hold atoms together to form molecules. Molecules are the most common form of chemical substances that we experience everyday in our lives. If you go to Tylenol on wikipedia there is a good example of information on the molecule and the chemical structure of Tylenol. In the upper right of the page there is a structure called a Ball and Stick model. This model represents atoms that are held together by chemical bonds. In this model (which is quite common for chemistry) the black balls represent carbon atoms, the white balls represent hydrogen atoms, the blue balls represent nitrogen atoms, and the red balls represent oxygen atoms. Notice that it is possible to have 1 or even 2 bonds between some of the atoms. The other image is called a Kekule Diagram. This is the short-hand method that scientists use to draw molecules. It is very common for scientists to not indicate the carbon and hydrogen atoms since these are so common in molecules it becomes quite tedious! So it becomes necessary to understand that the Kekule structures are short-hand notation for the more accurate Ball and Stick model. The other common information needed for molecules is the molecular formula (this is the count of each type of atom in the molecule) and the formal chemical name. While in wikipedia on Tylenol, if you click on acetominophen or paracetamol you come to a page that has the detailed chemical information on this common drug. On the upper right is the same images. Under the images you will notice the systematic or IUPAC name. This is the name that scientists call this molecule. Also on the right you will notice the detailed chemical properties for this molecule, one of which is the formula, C8H9NO2. So, in Tylenol there are 8 carbon atoms, 9 hydrogen atoms, 1 nitrogen atom and 2 oxygen atoms.
For this activity students are to explore the web and find chemical structures and names for everyday molecules. Remember Wikipedia tends to be a great resource for this info!
1. Post a picture of three 3-dimensional Ball and Stick molecular models(choose your three favorite molecules) that you have created with common items around your home (e.g., toothpicks and marshmallows). Also post a molecular structure image(image from the web, of either a Kekule Structure or a Ball and Stick Model) and the IUPAC name of the molecule.
2. Post an image from the web, the chemical systematic (IUPAC) name, common name, and the molecule formula for 20 chemicals that you use or eat. Explore the ingredients of things like cosmetics and foods.
3. Look over your molecules and the bonding characteristics, how many bonds does each of the following elements typically have? Carbon? Hydrogen? Oxygen? Back in your homemade structures, this would be the number of toothpicks attached to each element.
4. What does IUPAC stand for?
5. As you explore ingredients, notice how everything around us is made up of chemicals consisting of atoms bound together into molecules. But what about companies that claim their products are chemical free! How can this be? Here is an example:
Do a little web searching and propose what chemicals are actually in this product.
Thursday, June 16, 2011
Wednesday, June 15, 2011
For this activity review the Content Slides on D2L (Atoms and Atomic Structure) and complete the activities/questions below.
Make a model of your three favorite elements on the Periodic Chart. The models must be 3-dimensional and be made out of common objects around your home. Place photos of your three models with descriptions on your blog. Your models must include the appropriate number and positioning of protons, neutrons and electrons.
1. What is the atomic number for each of your models?
2. What is the atomic mass number for each of your models?
3. In your models, which two subatomic particles are equal in number?
4. How would you make an isotope for one of your models? What would change with the model?
5. Considering the overall volume of your element models, what makes up most of the volume of an atom?
6. For one of your models, show with another image what happens when energy excites an electron.
7. Once the electron is excited, what do we typically observe when the electron returns to the ground-state?
8. Why are some elements different colors when they are excited?
9. With the Fourth of July coming up quickly, explain how the colors of fireworks arise.
10. Explain the overall organizational structure of the periodic table.
11. List two example elements for each of these groups or classes: Alkali Metals, Alkaline Earth, Halogens, Noble Gases, Transition Metals, Non-Metals, and Metalloids.