pEnNiUm

Introduction:  Almost all elements consist of mixtures of two or more naturally occurring isotopes or atoms of an element that vary because they have different mass numbers  and numbers of neutrons.  The different isotopes of an element have a different relative atomic masses due to the different number of neutrons in the nucleus. 

Throughout this lab you are going to pretend that you have an element called "Pennium".  You'll be given a bag of Pennium atoms.  Through comparing the masses of the "penny atoms" you will see how many different Pennium isotopes are in the bag.  You will then determine the average atomic mass of Pennium isotopes using the following equation:  (average mass of isotope 1)(percent abundance of isotope1)+(average mass of isotope 2)(percent abundance of isotope 2).  Now, you will choose another element (Fivecentium) to be accepted as the mass standard to which mass of Pennium, Dimeium, Quarterium, and Halfdollarium.  All relative masses will be expressed in CMU (Coin Mass Units)

Objective: You will investigate the concept of atomic mass and how it was derived.  You will develop your own unit of measure, the CMU, and use it to measure the relative masses of other coins.  At the conclusion of this lab you will be able to explain how scientists developed the system for AMU's (atomic mass units) and how it is applied to determine the relative masses of other atoms of other elements.

Procedures- Part 1: 

1- Obtain a packet of pennies.

2- Sort the pennies into two groups:  pre-1982 and post-1982.

3- Measure the mass (in grass) of each stack of pennies.  Record the mass (in grams) of each stack of pennies in a data table.  Count the number of pennies in each stack.

4- Measure the mass in grams of a half dollar, quarter, nickel, and dime.  Record these values in a data table.

5- Answer the questions below and then continue on with part 2.

Results:     Pre-1982 Pennies        Post-1982 Pennies

Mass:                         42.4g                                27.5g

Number of pennies:   14                                       11

Average mass:         3.03g                                  2.5g

  
Results Cont.:                Nickel       Dime       Quarter
Mass:                                   5g            2.2g           5.1g
Mass in terms of nickel:     1N            .44N         1.02N

Questions- Part 1:

1- Does each penny have the same mass?

*No each penny does not have to same mass.

2- Can you identify two "penny isotopes" based on the masses of the pennies?  Explain?

*Yes!!! Pre-1982 is one isotope while post-1982 is another isotope.

3- What does your data tell you about the relationship between mass of a penny and date of a penny. Make a generalization. 

*Pre-1982 pennies weigh more than the post-1982 pennies.

Procedures- Part 2:
1- Determine the average mass of pre-1982 pennies. (Record average).
*3.03g
2- Determine the average mass of post-1982 pennies. (Record average).
*2.5g
3- Determine the percentage of your pennies that is pre-1982 and the percentage that is post-1982.  These percents should add up to 100%.  What you have calculated is the percent abundance of each group of pennies (penny isotope).
*post- 44%  pre- 56%
4- Let's choose one of your coins to make a CMU (coin mass unit).  Let's say that the mass of a nickel (Fivecentium) is one CMU.  Use the mass of a nickel to calculate the mass of a half dollar (Halfdollium), quarter (Quarterium), dime (Dimeium), pre-1982 pennies (Pre-82 Pennium), post-1982 (Post-82 Pennium).  Again, show all calculations, and record all data in a data table.
5- Determine the average mass of a Pennium in CMU's using the percent abundance (from #3) of each pennium isotope (pre-82 and posst-82) and the mass of each pennium isotpope in CMU's (from #4).
*(3.03x.56)+(2.5x.44)=2.8

Questions AND Conclusions:
1- Make a statement about the average penny mass of pre-1982, post-1982, and pennies in te packet. 
*New pennies, or post-1982 pennies, have more mass or are more massive than the pre-1982 pennies.
2- Explain how you derives the unit CMU. 
*We used the formula given to us in the introduction. (3.03x.56)+(2.5x.44)=2.8
3- Using the idea you explained in #2 above, how did scientists obtain the Atomic Mass Unit (AMU) to measure the mass of atoms of different elements?
*They used atomic mass average base to help find all of the elements' atomic masses.
4- What is your weight in CMU's? (Remember 1lb=2.205Kg),
*.00635lb
5- Write a statement that compares what you did in this lab to what scientists have done to find the average atomic masses of the elements.
*Scientist have used the same method with Hydrogen as the smallest form of measurement to help find the atomic masses of the rest of the elements.

Candy? Lab? What?

Purpose:

• To use a Candium model to explain the concept of atomic mass.
• To analyze the isotopes of Candium and calculate its atomic mass.

Vocabulary:
Atomic Mass: The weighted average of the masses of the isotopes of an element.
Isotope: Atoms that have the same number of protons, but a different number of  neutrons.
Percent Abundance: The percentage of each type of isotope that exists in a given sample of an element. 
Relative Abundance: The number of organisms of a particular kind as a percentage of the total number of organisms of a given area or community. Example: The number of birds of a particular species as a percentage of the total bird population of a given area.
Average Mass: Mass of all added together, and divide by how many there are.
Example: 4, 3, 2, 7. Add all together- 4+3+2+7= 16. Divide by how many there are- 16/4= 4. Average Mass= 4.
Relative Mass: It is the ratio of the average mass of a molecule (or formula unit) to the twelfth of the mass of one atom of Carbon-12.

Materials:

• Sample of Candium ( Gob Stoppers, Sixlets, M&M, Skittles )
• Balance
• An open mind!

Procedure:

1. Obtain sample of Candium
2. Separate it into its 3 isotopes
3. Determine the total mass of each isotope
4. count the numbers of each isotope
5. Record data and calculations in the data table careate a data table that has the following:

               1. Average Mass of each Isotope
               2. Percent abundance of each isotope
               3. Relative abundance of each isotope
               4. Average Mass of all isotopes
   Make a data table, it should have five colums and seven rows.


Our Data Table
                  Gob Stoppers          Sixlets          M&M's          Skittle's
Average Mass: 1.815 g               .888 g           .936 g             1.01 g
Percent Abundance: 37.1%                 24.1%          27.7%             11.1%
Relative Abundance: 6                         16                 13                  22
Relative Mass:  2.004 g                    1 g              1.05 g           1.14 g
Average Mass: .567 g                   .567 g          .567 g            .567 g
(of all isotopes)



Discussion
During the lab we calculated Atomic mass, and used a Triple Beam balance.

(For definition of Isotope, look up at Vocabulary)Explain the difference between Percent abundance and Relative Abundance...
Percent Abundance deals with the percent of the isotope that is in a sample of an element; Whereas Relative Abundance deals with the number of stuff in each Isotope.

Comparing the total values of average mass between relative mass:

The Relative mass has to do with the Isotope itself, whereas the Average mass deals with all the isotopes. 

ConclusionThis Lab was really good in seeing the Atomic Mass of Isotopes. Hopefully you gained an understanding for the material, and had fun like we did!

What is that... Ya THAT!!!!

Introduction:  What are the signs of a chemical change?  There are four different signs such as a change in color, bubbles without heat, form of a precipitate, and production of heat or light.  How can we witness all four of these evidences of a chemical change all in one lab?  If you follow these steps and do this aweesome lab you will witness all four of these changes!!!  Hope you enjoy :)

Hypothesis:  During this lab we will see a color change, bubbles, formation of a precipitate, and production of heat. 

Materials:

• One beaker- 150 or 250 ml
• Copper(II) sulfate pentahydrate- caution, toxic substance!!!!!!
• Scoopula
• 100 ml graduated cylinder
• Stirring rod
• Thermometer
• Small square of aluminum foil

Procedure: This lab is unique in that it serves both as an introduction to both the laboratory environment and as a review and demonstration of terms and concepts we have recently learned in lecture.  Thus, as you read and follow the procedure, be sure to answer all questions that are posed to you in the space provided.  

Data: During this lab the beginning temperature was around 21.  After we added the salt the temperature ended at just above 25. 

Discussion: During this lab we saw copper forming after we added the salt and foil.  This is a formation of a precipitate, one of our clues of a chemical change.  We also saw some bubbles forming without adding heat, the temperature rose, and the color of the foil changed. 

Conclusion:  We accept our hypthesis, during this lab we saw all the clues to a chemical change.

Bubbles??? Yes bubbles:)

Alright...So here's the problem. Would Salt or Sugar make a better bubble? Yeah I know, I know! You can't blow a bubble with just salt! But if you combine it with water and soap, you are in for a pretty fun experimient! So take a wack at this fun easy experiment and see for yourself if Salt or Sugar make better bubbles.

Materials:

• 3 plastic cups
• liquid dish soap
• measuring cup and spoons
• water
• table salt
• table sugar
• drinking straw

Procedures:

1. Label the cups; 1, 2, and 3.  Measure and add one teaspoon of liquid dish soap to each cup.  Use the measuring cup to add 2/3's cup of water to each cup.  Then swirl the cups to form a clear mixture.  CAUTION: wipe up any spills immediately so that no one will slip and fall.
2. Add a 1/2 teaspoon of table sugar to cup 2 and a 1/2 teaspoon of table salt to cup 3.  Swirl each for one minute.
3. Dip the straw into cup 1, remove it, and blow gently into the straw to make the largest bubble you can. Practice making bubbles until you feel you have reasonable control over your bubble production.
4. Repeat step 3 with the mixtures in cups 2 and 3.

Observation:

Cup 1; has green dish-detergent in it and water. Because of the green dish soap the water has a slight green color to it.

Cup 2; has green dish-detergent, water, and sugar in it. Like Cup 1, Cup 2 also has a slight green color to it because of the green dish soap. But it also has a slight milky color to it, when compared to Cup 1.

Cup 3; has green dish-detergent, water, and salt in it. Like Cup 1 and Cup 2, Cup 3 also has a green color to it because of the green dish soap. But when compared to Cup 1, Cup 3 is very very milky.

Hypothesis:

Starting with Cup 3. I'm guessing that Cup 3 will have a greater struggle making the bubbles. Only because the solution looks "heavy" compared to Cup 2 and Cup 1's solutions.

Next with Cup 2. Cup 2 do will do better than Cup 3 with making the bubbles. But still will have a slight sturggle seeing as there is sugar added to the solution.

Last Cup 1.  Cup 1 will do the best out of all of them. Since there is only dish soap in with water.

Experiment:

Cup 1: Bubbles are easy and smooth to produce. Bubbles don't require a gentle blow to make them. They can also be produced with a forced puff of air. Bubbles bounce and stick to surface for more than 10 seconds. Easy to make nice good sized bubbles. The color of the bubble is a good "rainbow".

Cup 2:  Bubbles are easy and smooth to produce. Bubbles don't require a gentle blow to make them. They can also be produced with a forced puff of air. Bubbles bounce and stick to surface for more than 10 seconds. A bit of a challenge to make nice good sized bubbles. The color of the bubble is a good "rainbow".

Cup 3: Bubbles are harder to produce. To make bubble you must blow gently and carefully. Bubbles pop easaly compared to Cup 1 and Cup 2. Color of bubble is more clear. Hard to make a good nice sized bubble.

Conclusion: 
While observing the bubbles produced by the solutions: cup 2 had the same ability to make bubbles as cup 1 but the bubbles in cup 1 were larger.  The solutions in cup's 1 and 3 had differences in their abilities to produce bubbles.  Cup 1 gave the bubbles a "rainbow" look while cup 3's bubbles were clear.  Cup 3 would produce bubbles but not any at a good size while cup 1 produced good sized bubbles.
The solutions with the table salt and sugar produced bubbles but they weren't as big as the solutions without.  Therefore it affects the ability for the solution to hold together while its being expanded by air.  Creating our own experiment we would change the salt to pepper and see the effects of pepper on the solution.  The hypothesis we created is that it will not have much effect on the solutions ability to create bubbles.