M&M ISOTOPES

Blue M&M’s = protons

Red M&M’s = neutron

WARNING: These candies have been handled by several people. Do not eat them under any circumstances. Also, place them back carefully when you have counted them.

PURPOSE - The purpose of this lab is to allow you to examine models of isotopes and analyze them for various characteristics.

MATERIALS - Eight labeled plastic Easter eggs, each containing a different number of protons and neutrons.

PROCEDURE - Examine each of the eight “isotopes” and fill in the correct information for each in the table below. Then answer the questions that follow.

DATA

Egg # / # protons / # neutrons / atomic # / mass # / element symbol
1
2
3
4
5
6
7
8

ANALYSIS AND CONCLUSIONS

1.   Write the isotope symbol for isotope #6. Include the element symbol, atomic and mass number.

2.   What is the other way to name this isotope?

3.   There are three isotopes of the same element among the eight isotopes. Which numbers are they?

What element do they all represent? Write their three symbols here.

4.   List the numbers of two isotopes which have the same number of neutrons.

Do these represent the same element?

Write the isotope symbols for each of these two elements.

5.   Look at isotope #3. If you had extra red and blue M&M's, how would you make another isotope of this element?

Is there only one way that this can be done?

6.   You want to make an egg which represents an isotope of aluminum. How many blue M&M’s will it contain? How many electrons would a neutral atom contain?

How many red M&M’s would the most common isotope of aluminum contain (hint – look at your periodic table!)?

7. A neutral atom of #8 would have how many electrons? If the electrons were stripped from the atom, what would be left? What is this called? (Hint: think of Rutherford’s experiment)

8. If atom #5 ejected your answer to the question above from its nucleus, what new element would be formed? (If you need to actually do this, open #5 again and remove the proper amount of M&M’s. You have just simulated radioactive decay!) Be sure to return the M&M’s afterwards!

9. Do you think that isotope #2 is the most common isotope of that element? How can you tell?

10. If the abundance of isotope #2 is 1%, #6 is 98% and #7 is 1%, what is the relative atomic mass of this element? (Show all your work.)