Beacon Lesson Plan Library

Finding the Spot

Rosemary Wilson
Santa Rosa District Schools


Students use circles to ‘home in' on particular spots, showing the ability of scientists to locate unseen objects in space. This activity shows how scientists know certain objects exist in space due to the forces exerted by adjacent bodies. The teacher i


The student knows that from time to time, major shifts occur in the scientific view of how the world works, but that more often, the changes that take place in the body of scientific knowledge are small modifications of prior knowledge.


- Activity sheets, one copy per student (See associated file)
- Rubrics, one copy per student
- Rulers, at least twenty-five per class
- Compasses, at least twenty, to be shared if necessary
- Pencils, supplied by the students


1. Prepare copies of the activity sheet “Finding The Spot”, one copy per student.
2. Prepare copies of the rubric for the related lab report, one copy per student.
3. Acquire rulers, at least twenty-five per class; students may have to share if you have a larger class.
4. Compasses – borrowed from the math department at your school.
5. Pencils, supplied by the students.
6. Place all supplied materials at a central location.


1. Begin a class discussion by asking the students if they believe black holes exist. After several students have given their opinions, ask the class if black holes can be seen even with the sophisticated optical instruments of today. Of course, the answer is ‘no’.

2. Ask the question; “Since you can’t see black holes, yet you believe they exist, do you think we are correct in our beliefs that an atom consists of protons and neutrons in the nucleus surrounded by electrons in the electron cloud?” Hopefully, the class will remember the information about the composition of an atom and reiterate that an atom is what we believe it to be.

3. Explain to the class that we have to use our available knowledge of forces acting in the universe to determine that unseen bodies, like black holes, exist as well as unseen particles like protons, neutrons, and electrons exist as the makeup of atoms.

4. Begin at one side of your class and tell the students to count off in repeating x, y, and z’s.

5. Distribute the lab activity sheets “Finding the Spot”, one copy per student, but give each student the lab sheet that corresponds with his particular letter. It is suggested that you distribute the rubric associated with this lesson, one copy per student, so students will know what is expected for their lab reports. Tell the students that the materials they will need for the exercise are located at a specific point. Tell them to start the activity as soon as they are ready.

6. As the students work to find their ‘spots’, walk around the room to provide assistance as needed.

7. Periodically ask the class which of them have finished the activity and found their ‘spots’. Do not use this question to determine that some students have not finished. Only use it as a determination of how soon you should address the next step of the procedure.

8. When all the students have finished, make the following pointed statements:
a. You did not know where your spot was located when you first started searching to find it.
b. The forces, actually the distances, acting on each other, provided you with the information you needed to find your spots.
c. Scientists have to use available information to discover the secrets of our universe, from the giant heavenly bodies to the smallest units of matter.
d. Sometimes, scientists make incorrect assumptions. The scientific community is constantly trying to determine if the hypotheses projected by our scientists are credible. The scientific community sometimes proves a hypothesis or theory incorrect, and sometimes, the community helps to provide studies that support the projected ideas.

You may include the following if you use this lesson during the chapter for atomic structure.
e. Rutherford used the concept of forces to determine the existence of the proton.
f. Thomson used the concept of forces to discover the existence of the electron
g. Chadwick had a more difficult when he searched for the elusive neutron. Since the neutron is neutral, he had no forces to use to discover its existence.

9. Ask the students if they have any questions or remarks. Allow for ample time to address the students’ questions.

10. Tell the students to complete their lab reports and submit them to you at the end of the lesson time. Make sure you explain that their reports will be assessed according to certain guidelines. You may find the attached rubric helpful and it is advisable to distribute copies of the rubric, as suggested above in step 5 of the procedures, to the students to make them aware of the characteristics of a well-accomplished report.


Students complete reports that will be checked and assessed according to a rubric. Both report criteria and rubric are located in the associated files. The students will provide ‘Conclusions’ for their reports so they can verbalize the point of the Sunshine State Standard that ideas of how the world works are formulated from scientists who take into account all the available information they can garner from technological advances that enhance information of prior knowledge. At the end of the activity, specific questions on the lab report will be asked that will directly address the Goal 3 standard. These questions are specific to determine the abilities of the students to see the relationship of this activity to the fact that scientists publish their theories based on their interpretations of the information they are able to garner from known facts applied to new discoveries.


This activity can be used in physics with the same concept of using the distances as applied ‘forces’ acting on a point. Students will find a 'spot' of interception in the same manner as this activity.

Attached Files

Finding the Spot - Spot 'X'     File Extension:  pdf

Finding the Spot - Spot 'Y'     File Extension:  pdf

Finding The Spot - Spot 'Z'     File Extension:  pdf

Rubric for "Finding The Spot"     File Extension:  pdf
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