Transparency Masters
1. Target for Activity 2
2. Target for Activity 2 with Radii Shown
3. Energy Level Diagram
4. Laboratory-Aids #100 Obscertainer Kit
5. Word Search



Student Worksheet and Guide
How many times have you looked at an object that attracted your attention and aroused your interest and asked
the question, What is it made of? That same question has been asked thousands of times in many different
languages. Because scientists continued to search until they found the answers to many of the problems they
faced, we today have the modern world as our home.
We can look back at some of the answers suggested by the early Greek philosophers (as the scientists were called
in those days) and smile. Today, even an elementary-school student knows, for example, that water is composed
to two substances, hydrogen and oxygen. The Greeks, however, suggested that the world itself was made up of
four elements of which water was one, and fire, earth, and air were the other three. Because of lack of careful
observation and experimentation, people accepted the idea suggested by the Greeks. This acceptance is seen in
our literary works where a storm, for example, is described as the raging of the elements. This idea was so well
established that it was not until the seventeenth century that scientists established the fact that the Greeks were
mistaken and science came closer to the answer it sought.
Most individuals consider themselves good observers. This laboratory activity involves many things, mainly,
making careful observations and checking the accuracy of the hypothesis or best guess.
It is important for a science student to practice making useful observations even if they are not immediately in
the complete solution of a problem. In this laboratory activity, you will begin by observing by indirect means. In
order to solve the problem it takes concentration, alertness to detail, ingenuity, and patience.
Problem: What is the configuration (design) of the inside of a closed container (OBSCERTAINER)?
Theory: This laboratory activity is an exercise in indirect measurement or observation. The closed
OBSCERTAINERS have partitions inside and a steel ball that can freely move. You will not be
able to see or touch the inside of the OBSCERTAINER and yet you will have to determine the
design of the inside by indirect means.
Procedure: Move the steel ball around by carefully shaking and tilting the OBSCERTAINER. By the sound
and path of the steel ball, determine the shape and location of the partition(s). In the blanks
below, indicate the identity of the OBSCERTAINER (its number) and your hypothesis. Retest
your hypothesis and indicate any changes in the second drawing. This should reflect your final
Some of the OBSCERTAINERS are more difficult than others, therefore time should be spent
in making careful observations. Do not spend more than six minutes with each OBSCERTAINER.
four different containers.

1. Write a summary of the actual OBSCERTAINER configuration and your hypothesis (conception) of it. List those
things that you were able to determine and those that you were unable to determine.
2. Is there any reason why you were successful for certain characteristics and not for others?
Word Search
Words about the concepts in this module can be obtained from the clues given.
Find these words in the block of letters:
1. Difference in the mass number and the number of protons is equal to the
number of ____.
2. Region of space where there is a high probability of finding an electron.
3. Quantum number that identifies the shell where the electron can be found.
4. Acronym for the order of colors in the visible spectrum.
5. Where protons and neutrons are found.
6. Atoms with the same number of protons but different numbers of neutrons.
7. Having only discrete values possible.
8. Distance between successive peaks in a wave.
9. He stated that all orbitals of equal energy are first occupied by single
electrons before any orbital is doubly occupied.
10. Number of protons in an atomís nucleus is symbolized by this letter.


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