Monday, July 11, 2011

Activity 8

1. Choose any Teaching Idea from any of the Chemistry Simulations (http://phet.colorado.edu/en/simulations/category/chemistry ) and post your results/data and/or answers on your blog.

MOLECULES and LIGHT Today you are going to use a sim to explore how light interacts with molecules in our atmosphere. I.
What are some of your observations?

Nitrogen is basically unaffected by all types of light.  The ozone layer goes through a lot of stress from light that is not natural.  Oxygen and water are affected in a light manner as well.
Explore the sim with a partner.
II.
What patterns did you find? What ideas do you have about how the sim relates to your everyday life?
 The ozone is basically affected by all un-natural light.  It is hard to do anything to carbon monoxide as well as nitrogen.  Oxygen and water are only affected by certain light.

Explore what happens for each type of light. III.
What patterns did you find?
Based on your observations, how would you predict HCN to interact with microwaves?
All are affected by:
Carbon Monoxide-- microwave and infrared
Nitrogen--None
Oxygen--None
Carbon Dioxide--infrared
Water--microwave, infrared
Nitrogen Dioxide--All but visible
Ozone--All but visible
IV.
What do you think is happening?
Look closer at how infrared light affects water in the sim or in the movie below.
Explore what happens for each molecule. It is taking a closer look at the temperature of the water.  In turn it is showing movement and heat or cold spots while interacting with molecules in the water.
V.
 Microwaves How do microwave ovens work?

"Microwave ovens take advantage of the behavior of water molecules when subjected to electromagnetic waves found in the microwave band. "
http://www.universetoday.com/45527/how-do-microwaves-work/
2.
Greenhouse effect What is a greenhouse gas?

3.
Ozone layer Why is the ozone layer important?
2. Work with any of the Chemistry Simulations to create your own Teaching Idea. The criteria for this is as follows:
a. must identify and meet three (3) science education standards

b. must be original work

c. must be scientifically accurate and appropriate for the directed grade level.

Balloons and Static Electricity

Objectives:  Fourth Grade students will be able to get a better handle on static electricity while still having fun.

1.  Students will visit the Balloons and Static Electricity simulation page.  This will give the students a better idea of what static electricity is all about.  They will also be asked the question:  Who knows what static electricity is?  Do you know how it is made?
http://phet.colorado.edu/en/simulation/balloons

2.  After a brief session and overview of static electricity, students will partner up and be given a balloon which has already been inflated.  By now the students will have learned that static electricity is gained and lost through positive and negative charges.  This was explained in the simulation.

3.  Students will be able to experience static electricity first hand.  They may use their shirts, hair or other materials in order to make their static electricity.  This will give students an in depth and up close experience with static electricity and how it is conducted.

4.  The students will answer a set of brief questions including:

How is static electricity gained or lost?
How can we make static electricity?
What were some basic observations you made during this experiment?
Do you now have a better understanding of static electricity?
What will happen to the balloon if it is positively charged and placed on another object?
Students will also be required to draw a picture of what is happening and of any changes they may see.


Science Standards:

D.4.5 Construct simple models of what is happening to materials and substances undergoing change, using simple instruments or tools to aid observations and collect data

While going through the experiment, students will record data and make pictures to better understand what is happening during the experiment.  There will be change occurring and students will notice these changes.

C.4.2 Use the science content being learned to ask questions, plan investigations, make observations, make predictions, and offer explanations

In the beginning of the experiment the students will be asked to predict what will happen with static electricity.  Over the course of the experiment, the students will be able to give a better answer to the balloon theories.  They will also be able to make observatins and be able to explain themselves better.

C.4.5 Use data they have collected to develop explanations and answer questions generated by investigations

By investigating the project in a hands on manner and drawing pictures, the students will be able to answer some of their own questions that they may have when we start the experiment.  It will make much more sense after the children are able to experience the experiment hands on.


1.
Pick one of the topics below to study in more depth. Prepare to share your ideas with the class by making sense of what you discover.

Activity 7

1. Review the Content Slides Acids and Bases on the D2L site.
 Check!

2. Complete the Teaching Idea “Concept Questions for Chemistry using PhET”  posted by Trish Loeblein on the pH Scale simulation at PHET (http://phet.colorado.edu/en/simulation/ph-scale). On your blog post the answers with your scientific explanations from the “Clicker Questions pH Scale” posted by Trish.



 
1. There are 2 balloons in a room. They are identical in size and material. One balloon is filled with air and the other balloon is filled with Helium. How does the pressure of the air balloon compare to the pressure of the Helium balloon. The pressure in the air balloon is A. less
2. How does the pressure in the Helium balloon compare to the pressure of the air in the room? The pressure in the Helium balloon is
C. greater

3. How do the number of air molecules in the air balloon compare to the number of He atoms in Helium balloon? The number of air molecules is
A. less
4. How does the average speed of the Helium molecules compare to that of the air molecules? The average speed of the He molecules is C. greater
5. What will happen to the pressure if temp is held constant and the volume is decreased?
 
B.Pressure goes up because more collisions are happening, but same force per collision

6. You are flying from Denver to Boston, and you bring along a ½ full bottle of shampoo that was well sealed before you left Denver. You land in Boston and proceed to your hotel. The number of air molecules within the shampoo bottle:
C. has increased
7. If the walls of the shampoo bottle are strong and rigid so that the bottle has the same shape as before you left, how does the pressure of the air inside the bottle compare to the pressure of the air in Denver?
 
C.greater than
8. How does the pressure inside the bottle compare to the pressure of the air in Boston?
 
C.greater than
9. If you had a water bottle with very soft sides. When you open your suitcase in Boston, the bottle would look
 
C.puffed out
3. Complete the Teaching Idea “Intro to Strong and Weak Acids and Bases” posted by Chris Bires on the Acid-Base Solutions simulation (http://phet.colorado.edu/en/simulation/acid-base-solutions) and post on your blog your data and answers to the questions posed.


Strong Acid
Weak Acid
Strong Base
Weak Base
Water
pH meter read
(value)
2.0
4.5
12.0
9.5
7.0
pH paper
(color)
red
orange
blue
green
yellow
Conductivity
(bright/dim/none)
bright
dim
bright
dim
very dim
Exists as Mostly
(ions/molecules)
ions
molecules
ions
molecules
molecules



Strong Acids

Strength
Initial Acid Concentration (mol/L)
[HA] (mol/L)
[A-] (mol/L)
[H+] (mol/L)
pH
.010 M




.050 M




.100 M




1.00 M





Weak Acids

Strength (approximately)
Initial Acid Concentration (mol/L)
[HA] (mol/L)
[A-] (mol/L)
[H+] (mol/L)
pH
.015 M




.150 M




.015 M




.150 M





Strong Bases

Strength
Initial Acid Concentration (mol/L)
[MOH] (mol/L)
[M+] (mol/L)
[OH-] (mol/L)
pH
.010 M




.050 M




.100 M




1.00 M





Weak Bases

Strength (approximately)
Initial Acid Concentration (mol/L)
[B] (mol/L)
[BH+] (mol/L)
[OH-] (mol/L)
pH
.015 M




.150 M




.015 M




.150 M





Conclusion Questions:
1.      A strong acid is very concentrated
2.      A weak base is a weak electrolyte.
3.      A strong base is a strong electrolyte.
4.      At the same concentration (Molarity) a strong acid will have a lower pH as a weak acid.
5.      As concentration of a weak acid increases, the pH decreases.
6.      As concentration of a weak base increases, the pH increases.
7.      As the concentration of a weak acid increases, the number of ions increases.
8.      As the concentration of a weak acid increases, conductivity increases.
9.      As the strength of a weak acid increases, the proportion of ions to molecules decreases.
10.  As the strength of a weak acid increases, the conductivity increases.
11.  What are the pH values of a weak acid with a concentration of 0.10 and a strong acid with a concentration of 0.01, ten times lower?     Weak acid, 0.10 M :_______4_____    Strong Acid, 0.01 M :_____2_______