Atoms: Is it full?

Fill a large, clear container with rocks/pebbles/marbles.  Ask your students, "Is it full?"  They will answer, "Yes," as no more pebbles can fit in.

Now pour sand in over the pebbles until the container can hold no more sand.  Ask your students, "Is it full?"

Finally pour water in over the sand and pebbles until the container can hold no more water.  Ask your students, "Is it full?"

At this point, you'll get some students convinced that it is full, but others will now be skeptical, based on what you've showed them so far. 

Ask those students, "What else would fit in this glass?"  You're working toward the idea of atoms being tiny particles, so small (some of them) that they could squeeze in between the molecules of water.  Once students have an idea of how small atoms are (sort of, it's awfully hard to truly understand how minuscule they are), you can proceed with your study of atoms. 

Periodic Table: Sticker Atoms

Each year, aAfter my students had learned about atomic structure and were beginning their periodic table investigation, they each chose an element to research a bit.  Every year I varied the product they produced a bit - variations on the element models and an element block (watch for more information on that one coming soon). 

One year, in addition to making their block, I had them create a sticker picture of their element. 

Each student was given a piece of black paper, blue dot stickers for protons, green dot stickers for neutrons, tiny smiley face stickers for electrons and a white colored pencil. 

Making the picture was not particularly challenging - though some interesting questions did arise about electron orbitals for students who were doing transition metals. 

The reason for making the picture wasn't in the interest of challenging the students, but instead to create a giant periodic table.  I laminated each of the individual pictures and then assembled them using clear packing tape. 

This periodic table does a nice job of showing the enlarging nuclei and increasing electron orbitals.  And by taking part in making the table, the students were much more invested in the process and obtained greater understanding of how their element fit in the periodic table.

FYI:

I had three classes of students and each student had to choose a unique element.  Each class was informed of the parameters during class time and element choosing "opened" at the end of the school day - so each student had equal opportunity to have the first choice.

In addition, I had a few students who helped make pictures for some of the elements that weren't chosen, so we had a more complete periodic table - at least for the first several periods. 

Atoms/Periodic Table: Bingo

Have students fill in a blank bingo card with any numbers between 1 and 50.

You can make up your own clues involving elements' atomic numbers, protons, electrons, and neutrons, or you can use mine:

1 - # of protons in Hydrogen
2 - # of neutrons in Helium
3 - # of electrons in Lithium
4 - # of neutrons in Lithium
5 - # of protons in Boron
6 - atomic number of carbon
7 - # of neutrons in Nitrogen
8 - # of electrons in Oxygen
9 - atomic mass of Beryllium
10 - # of protons in Neon
11 - atomic number of sodium
12 - atomic mass of Magnesium
13 - # of in Aluminum
14 - # of protons + # of neutrons in Nitrogen
15 - # of protons in Phosphorous
16 - # of protons in Sulfur
17 - # of electrons in Chlorine
18 - # of neutrons in Chlorine
19 - # of protons + # of neutrons in Fluorine
20 - # of neutrons in Potassium
21 - atomic number of Scandium
22 - # of protons in Titanium
23 - # of protons + # of neutrons in Sodium
24 - atomic mass of Magnesium
25 - # of electrons in Manganese
26 - # of neutrons in Titanium
27 - atomic number of Cobalt
28 - # of protons + # of neutrons in Silicon
29 - # of protons in Copper
30 - # of protons in Zinc
31 - # of electrons in Gallium
32 - atomic number of Germanium
33 - atomic number of Arsenic
34 - # of protons in Selenium
35 - # of neutrons in Zinc
36 - # of electrons in Krypton
37 - atomic number of Rubidium
38 - atomic number of Strontium
39 - # of protons in Yttrium
40 - atomic mass of Argon
41 - # of electrons in Niobium
42 - # of neutrons in Arsenic
43 - atomic number of Technetium
44 - # of protons in Ruthenium
45 - atomic mass of Scandium
46 - # of  electrons in Palladium
47 - # of electrons in Silver
48 - # of protons + # of neutrons in Titanium
49 - atomic number of Indium
50 - # of protons in Tin
I recommend making up a list ahead of time, to make sure you don't use the same number over and over while completely skipping others.

I wrote my clues on index cards.  Then, for each round I shuffle the deck and draw the cards from the top.

Atoms: Tasty Atomic Models

If you teach your students about the Thomson, Rutherford, Bohr and Heisenberg/Schrodinger models of the atom , you need to use this activity.  It's from Roseann McCarthy at Ocean Township High School, New Jersey and it's super fantastic.

Put your students in groups of four. 

Give each group a bag containing:
--A chocolate chip cookie
--A Tootsie Roll pop (or a Blow Pop)
--A Gobstopper
--A Ferrero Rocher chocolate

The students examine the candies/cookies and discuss which item best illustrates each model of the atom and why.

I like to have students explain why the item is a good model as well as provide a reason why it is not perfect and brainstorm ideas for other objects that would work to represent each atomic model.


Thomson - Chocolate Chip Cookie
Thomson described the atom as having negative charges scattered throughout it, like the cookie has chocolate chips scattered throughout it. 

Rutherford - Tootsie Roll Pop
Rutherford first proposed the idea of a nucleus.  The Tootsie Roll pop has a dense Tootsie Roll center, or nucleus.

Bohr - Gobstopper
Bohr placed electrons in energy levels, or layers outside the nucleus.  Gobstoppers change colors as the oustide dissolves because there are many layers of color.

Heisenberg/Schrodinger - Ferrero Rocher
The Heisenber/Schrodinger model places electrons scattered outside the nuclues - they care in a predictable space but no exact location can be identified.  The Rocher candy has a hazelnut center (nucleus).  In addition, there are chopped hazelnuts in chocolate surrounding the center - those pieces of nut are found in a specific region, but we can't pinpoint exactly where each piece of nut will be.

In case you aren't familiar with the Ferrero Rocher candies, here's a picture of one, cut through the middle:

At the end of the activity, I allow the groups to divide the items as they see fit.  Sometimes serious negotiations take place, but I've never has it turn into an argument (if it looks like it might, all you have to do is threaten to dispose of all the items for them).

A few more ideas/extensions:
--You can add Dalton's orginal atom as a sour ball or other piece of hard candy that's the same throughout.
--You might want to have a knife available, in case a group needs to cut one of the items open.  Keep it in your possession and you can do the cutting as directed by the group.
--If you can't bring candy into your classroom, take pictures of the candies and let the students work them out that way.  By using materials familiar to the students, they will develop a greater understanding of the models.  Going through the Ferrero Rocher model really helped me understand electron clouds better. 

Half-Life: The Penny Model

If you're introducing your students to the concept of half-life, things are probably seem a bit fuzzy for them.  Let them get some hands-on experience and see if things don't come a bit easier.

A quick review for anyone who may not have done this in awhile...
...half-life is the amount of time needed for half of the atoms in a sampleof a radioactive isotope (one form of an element) to deacy, or reach a stable state.  Some isotopes have half-lives that are a matter of seconds - they decay and become stable rapidly.  Other isotopes have half-lives that are thousands of years. 

Now, on with the show!

Start with 100 pennies.  Put them all in a cup, place your hand on the top and shake.  Dump the pennies out onto the table.  Remove all of the pennies with heads up (or tails, it doesn't matter, just pick one and stick with it).  Count and record the remaining pennies.  You have just completed one half-life.  Repeat until you are down to one or no pennies. 

Have students graph their data.  It's always good to practice graphing, and it helps some students visualize what's happening (and the graph for half-life will always take the same shape - the numbers and units on the axes may change, but the shape of the curve is always the same).

Now you can pose some questions to your students....
If someone walked by and saw that you had 7 pennies remaining, could they determine how many half-lives (shakes) you had completed?  How? 

And then take it into the real-world application of carbon dating....
Imagine that while digging in your yard, you uncover what appears to be a very old bone.  Through the help of a scientist at the lab, you're able to learn that the bone contains 12 pug (picomicrograms) of carbon-14 and that it contained 100 pug of carbon-14 when it was buried.  Carbon-14 has a half-life of 5730 years.  How old is the bone. 

P.S.
I did come across one criticism of this activity online, and I thought it was worth mentioning.  This person suggested that you needed to replace the "decayed" pennies with something else, because they decay, they don't disappear.  I thought it was a valid point, and in thinking about it was a little surprised that I've never seen that mentioned as a part of the activity. 

I'm thinking the small counting chips that you might have for games of bingo would be great - a similar size but definitely different from pennies would work great.  Kernals of popcorn would also be an inexpensive item to use.  Let me know if you think of something else. 

P.P.S.

If your students have been super good (or it's immediately following Halloween and you have a plethora of left-over candy), you could also complete this activity using M&Ms or Skittles. 

Atoms: Atom Models

For a couple of years, I have assigned Mr. Niven's Atom Project to my students. I have typed up my own instructions (as some of his statements wouldn't make sense to my students), but required the same elements as Mr. Niven. I've greatly enjoyed the resulting projects and appreciate the "able to hang from the ceiling" requirement. Getting them to hang is a bit of a chore, but once they're up, they're enjoyable to look at and they don't take up precious space on lab tables or elsewhere.

Once the projects have been turned in, I like to have students take turns sharing the information they found. To keep other students paying attention, I have them take notes of the highlights. Then, after everyone has presented, they are given a brief quiz ("This element is the most abundant in the universe.") during which they can use their notes. For students who have paid attention, it should be an easy way to boost their grade.

FYI The models pictured here were created by my students. And, with regard to the second model, it did have the appropriate number of electrons... they started to fall off while being stored.

Atoms: Rutherford's Gold Foil Experiment

This is an original demonstration I created to try to help my students understand Rutherford's experiment: what he expected to have happen, what actually happened, and why it was significant. The demonstration is a bit crude (and it's starting to fall apart) - there's certainly room for improvement, but I think it does help students visualize what was happening. Please let me know if you find a way to improve upon this demonstration - I would love to hear about it.

Prior to Rutherford's experiment, the going theory about the atom was Thomson's Plum Pudding model. In this model of the atom, negatively charged material is scattered throughout the atom.

In Rutherford's Gold Foil experiment, he set out to shoot a beam of atoms at a thin sheet of gold foil. Based on the Plum Pudding model, one would expect most of the atoms to bounce back because the "negative" material is scattered throughout the atom, not allowing much room for atoms to pass by.


Instead, most of the atoms went straight through the gold. The resulting conclusion was that gold atoms must be made mostly of empty space, with a large central nucleus.



To create my stunning visual aids, I collected:
*a couple dozen small (~1") styrofoam balls
*a styrofoam disk (~2" in diameter)
*2 empty cereal boxes (on the larger size)
*thread
*a very large needle (used for upholstery)

Box 1: Thomson's Plum Pudding Model
-Cut open the sides of your cereal box, I left them on as flaps, to protect the model.
-Use the needle to sting the styrofoam balls onto the thread. (I used about 4 balls per thread and about 6 threads - adjust to the size of your box accordingly)
-Tape the ends of the threads to the top and bottom of the box.

Box 2: Rutherford's Model
-Cut open the sides of your cereal box, I left them on as flaps, to protect the model.
-Use the needle to run the thread through the styrofoam disk. Instead of trying to poke the whole way through the diameter of the disk, I ran thread through two holes that were poked through the flat part of the disk (examine the above picture).
-Tape the ends of the threads to the top and bottom of the box.

To demonstrate:
Rutherford thought he was shooting atoms at something resembling Thomson's model. Use an extra styrofoam ball and toss it at Box 1. The majority of the time, the ball should bounce back, because there isn't room for it to fit through. This is what Rutherford expected to have happen.

But... that's not what happened. Instead most of the time the atom (ball) passed through. Pull up Box 2 and toss the ball at it. This time, the ball should pass through a lot of the time. The only time it will bounce back is if it hits the nucleus.