Judith A. Puglisi
Related Vocabulary
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21. nucleus: small, dense positively charged center of an atom.
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22. proton: subatomic particle that has a positive charge and is found in the nucleus of an atom.
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23. neutron: subatomic particle that has no electric charge that is found in the nucleus of an atom.
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24. electron: negatively charged subatomic particle found in an area outside the nucleus of an atom.
Before you introduce the concept of subatomic particles, make a model of a lithium atom from wire, modeling clay, and string. You can find detailed instructions for this model in Janice VanCleave’s book entitled MOLECULES. After you present the material on subatomic particles show the students the model of the lithium atom. Ask the students to identify the parts of the model. When using the model, make it very clear to your students, that this is not what a real atom looks like. Nor is this model showing the actual location of the electrons. This type of model, which is commonly referred to as “Bohr’s Model”, does represent the number electrons and energy levels a certain atom possesses.
As scientists continued to investigate and experiment they gained new knowledge that forced them to modify Dalton’s theory. Niels Bohr, J.J. Thomson and Ernest Rutherford were all scientists who contributed to the wealth of Knowledge we now have regarding subatomic particles. The three main subatomic particles are the proton, the nucleus, and the electron. They are called subatomic because they are smaller than an atom.
The nucleus is the “core” of the atom. It makes up 99.9% of the atom’s mass. And at the same time it is the smallest part of the atom. The nucleus is one hundred thousand times smaller than the entire atom. It is in the nucleus where the protons and neutrons are located. While the electrons can be found orbiting around the nucleus.
Protons are positively charged particles found in the nucleus of every atom. All protons are identical regardless of the element in which they found. Neutrons like protons are found in the nucleus and are also identical to all other neutrons regardless of the element in which they are found. Neutrons have no charge.
Electrons are very small particles that whirl around the nucleus of the atom. Electrons have a negative charge. If the atom is neutral, meaning it has no charge, the number of negatively charged electrons is equal to the number of positively charged protons. Electrons seem to be locked into a certain area around the nucleus depending upon how much energy the electron has. Electrons with low energy are found closest to the nucleus. Electrons with more energy are found farther away from the nucleus. Each energy level has a maximum number of electrons it can hold. The first level will fill up first and will hold up to two electrons. The second and third will hold up to eight electrons each. It is the arrangement of the electrons which gives an element its chemical properties. (14)
After students have been introduced to the structure of the atom, they will be required to make an atomic model of one of the elements using wire, clay and string. Put the name of the first sixteen elements each on a separate piece of paper. Place all the pieces of paper into a large beaker. Students will pick the name of the element that they must represent. Depending on the available space in the classroom, you may chose to have students make models of all the elements of the periodic table. As each students finishes their model, they must write an explanation of why they depicted their element as they did. Ask the student to answer questions such as “Why do you have five protons in the nucleus?” After the teacher has met with each student to discuss their model and reviewed the written explanation, the student may start to research their element. After the student has finished a written report on their element, they must create a riddle about their element that can be answered by reading their report. The teacher will type all the riddles and display reports around the room. The students will have to answer all the riddles by reading their classmates reports. Students who have difficulty reading can be paired with a strong reader. Companies are starting to put out high interest talking science software. Students with severe writing disabilities can use voice activated word processing programs.
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Notes
1. Information obtained from a Richard Lavoie lecture on “Learning Disabilities” CLCD conference 1994
2. This activity was adapted from content contained in J. Stepans and Lois Veath’s article How Do Students Really Explain Changes in Matter? (Science Scope, May 1994)
3. Content information obtained from Cooper, Christopher, Matter, pages 8-11.
4. Activity from Ardley, Neil, The Science Book Of Water.
5. Content information adapted from Maton, Anthea, Matter: Building Block Of The Universe, chapter 2.
6. Activity suggested by seminar leader Professor Michael McBride.
7. Activity from Ardley, Neil, The Science Book Of Water.
8. Content information adapted from Roa, Michael, Environmental Science Activities Kit.
9. Activity from Council of Environmental Education, Project WET.
10. Content information adapted from Maton, Anthea, Matter: Building Block of The Universe, chapter 5.
11. Content information adapted from Maton, Anthea, Chemistry of Matter chapter 2.
12. Activity from Mebane, Robert, and Rybolt, Thomas, Adventures with Atoms and Molecules.
13. Information obtained from J. Stepans and Lois Veath’s article How Do Students Really Explain Changes Matter? (Science Scope, May 1994)
14. Content information adapted from Maton, Anthea, Matter: Building Block of The Universe, chapter 3.
