Becky Zemple Prior Knowledge Assessment Lesson Plan 8 th Grade Physical Science through Atomic Theory

Transcription

1 Becky Zemple Prior Knowledge Assessment Lesson Plan 8 th Grade Physical Science through Atomic Theory Purpose: This lesson is designed to help students understand the basis of the atom and how its development occurred throughout history. It will reference those scientists whose ideas changed the way an atom was viewed. The lesson will also continue and review the periodic table elements and symbols. Given the PPT, foldable, and element model construction, students will be able to identify the atom models proposed by various scientists, have a general understanding of the theory paired with each model, and be able to give the number of protons, neutrons, and electrons of each atom s element on the periodic table. Safety Issues: The teacher will be using isopropyl alcohol and water for a demonstration. Risk of exposure to alcohol is a risk and safety precautions should be taken to avoid exposure to students. Students will be handling different supplies for building atom models. They may be exposed to toxics through glues or other materials being used; however, the risk is of exposure is minimal. Relevant Virginia SOLs: PS.3 The student will investigate and understand the modern and historical models of atomic structure. Key concepts include: a) the contributions of Dalton, Thomson, Rutherford, and Bohr in understanding the atom b) the modern model of atomic structure PS.4 The student will investigate and understand the organization and use of the periodic table of elements to obtain information. Key concepts include: a) symbols, atomic numbers, atomic mass, chemical families (groups), and periods Materials and Resources: Atomic Model Timeline Foldable Activity Sheet Pencils Isopropyl alcohol Distilled water 50 ml and 100 ml graduated cylinders Markers Glue/Glue sticks Construction paper (various colors) Procedures for Teaching: (2-50 minute classes) DAY 1 Engage: The teacher will engage the students by providing a focus question: 50 ml of water + 50 ml of alcohol =?, followed by demonstrating the discrepant event Doesn t Equal 2? with isopropyl alcohol and water. The teacher will measure 50 ml of water and 50 ml of isopropyl alcohol to show it does not equal 100 ml. (5 minutes)

2 Explore: Students will explore the atomic theory by completing the Atomic Model Timeline foldable activity sheet using the provided PPT lecture demonstration by the teacher. (35-40 minutes) Explain: The teacher will explain how to understand and visualize the different atomic models by introducing the students to the prepared models (made before class by the teacher) from each scientist discussed in the PPT. (5 minutes) DAY 2 Engage: The teacher will engage the students by reviewing the Doesn t Equal 2? discrepant event that was demonstrated yesterday by initiating a class discussion. (5 minutes) Explore: Students will review their previous work on the periodic table and examine its relation to the atom and its structure. (5 minutes) Elaborate: Students will be assigned an element from the periodic table. Using the provided materials, each student will be given the task of completing a model of an atom of their element with its corresponding atomic number, symbol, and number of protons, neutrons, electrons, and valence electrons. (30-35 minutes) Evaluate: Students will be asked to present their finished model with an explanation of how they completed the numbers of protons, neutrons, electrons, and valence electrons to the teacher at the end of the class period see rubric below. (5-10 minutes) Performance: 1 - Poor 2 - Fair 3 - Good 4 Very good 5 - Excellent Focus on assignment Correct numbers of element Completion of atom of element Understanding of concept Total Points:

3 Directions: Cut the flaps along the dotted lines. Write important facts about each atomic model and the scientist who created the theory on each flap. Glue this side down into your science notebook. A dot is a lot! These images are from BrainPOP.com and the ppt file located at PowerpointsWeb/Ppoint- AtomicModel.pdf Liz LaRosa 5th grade science

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5 Becky Zemple Prior Knowledge Assessment Reflection NSTA 8b NSTA 8b assessment states that teachers of science must demonstrate that they use the results of assessments as vehicles for students to analyze their own learning engaging students in reflective selfanalysis of their own work. Conducting a lesson plan based on prior knowledge of several students to address common misconceptions was an excellent way to address this particular assessment. Because the students I was interning with were due to learn about the atomic theory and atoms, I used the opportunity and conduct interviews about this topic to correct any misconceptions students may have about the atomic theory, scientists who discovered the atom and its parts, as well as the atom itself. Three 8 th grade students were interviewed and asked the same questions both before and after the two-day lesson plan. They were first asked, What is an atom? Student 1 replied, I don t know, a source of energy or something I don t know, I m not very good at this. Student 2 replied, it contains a nucleus with protons that are surrounded by rotating electrons. Student 3 replied, it s something that s little it has to do with matter. A little thing inside your body? When asked how big an atom was, I received replies from, as big as it can get, as little as it can be some atoms are so little you can t see them yeah to it s the smallest thing, to not really big. Only the second student had somewhat of an idea as to what an atom really was. One student said it couldn t be seen, while the other two said you could see it with a magnifying glass, a microscope, or a telescope. When asked what was inside of an atom, student 1 said, energy and shrugged. Student 2 said, protons, neutrons, electrons. Student 3 said, I don t know. After this question, they were asked to draw an atom (see Figures 1, 2, and 3). Student 1 was confused between a cell and an atom whereas students 2 and 3 had a good general idea of what comprised an atom. The students were asked who discovered the atom. I received replies from Albert Einstein, to Bohr, to another I don t know. All the students did know that atoms are found in everything. Lastly, the students were asked if all atoms look the same. Student 1 replied, No, things inside do different things. It can be a square or a glob, or like a line with things inside of it. I guess it could be anything. Student 2 replied, no, there s different kinds, but they re all the same sizes. Student 3 replied, no, they have different amounts of electrons. I asked if they were the same size and he said yes. When conducting the lesson, I began with a focus question to address the last question asked of the three students interviewed, 50 ml water + 50 ml alcohol =? Nearly all the students put 100 ml, which led into the discrepant event entitled Doesn t Equal 2? I measured 50 ml of tap water in one graduated cylinder and 50 ml of isopropyl in a second graduated cylinder (with help from students to check my measurements). Next, I combined them both into a larger graduated cylinder where the solution was again measured by a student and only gave about 97.5 ml. By engaging the students in this discrepant event, they were interested in the topic from the beginning because they did not understand why the solution did not equal 100 ml. I used a PPT presentation as well as classroom discussion to complete an Atomic Model Timeline foldable activity sheet during the class period. The students learned about the development of the structure of the atom we know today by discussing the various models I had prepared as well as the PPT about each scientist included in the timeline foldable. The questions of what was inside an atom and who discovered an atom were addressed to help provide the students with a better understanding of the atom and atomic theory. The same three students were interviewed one week after the lesson was conducted to see if their misconceptions and lack of knowledge were rectified. One problem was encountered, two of the students (1 and 3) were absent during the lesson and only received the information in a review by the cooperating teacher. Student 1 knew that protons and neutrons were inside the atom instead of energy but did not retain any information from the review. Student 2 had great prior knowledge and fixed his misconception about all atoms being the same size and remembered that John Dalton developed the atomic theory. Student 3 only retained the information that an atom contains a nucleus, electrons, protons, and electron holding shells from the review, whereas previously, she did not know. The students each drew another picture of an atom; though they did not change much due to the absence of students 1 and 3 (see Figures 2, 4, and 6).

6 Based on the research done by Baker and Piburn (1997), it is common, especially in the middle school age for students to have misconceptions about matter and atoms in general. They have difficulty picturing things they cannot see, at the microscopic level and smaller (or abstracts). They may compare microscopic things to bacteria or specks of dust. The students also believe that atoms vary in shape and movement depending on their state and substance. Baker and Piburn s data still seem to be very accurate with the misconceptions I heard and saw during the interview and lesson I developed and conducted with students at the 8 th grade level; however, due to the absence of two chosen students being interviewed during the actual lesson, the data was not completely accurate because they did not receive the information I provided based on their prior knowledge and misconceptions. Though some data was retained through the review the cooperating teacher provided, I now come to realize how important it is to continuously review material for students in order for them to retain the information. One teacher at my placement school mentioned that students have to be exposed to material or concepts 50 times before they retain it. Because of this need for repetition to retain knowledge, it is so important for teachers to be sure they recognize any prior knowledge and misconceptions the students may have before teaching a lesson. This way, teachers can address these misconceptions in multiple ways to help students remember the correct information.

7 Figure 1: Student 1 Atom Before Lesson Figure 2: Student 1 Atom After Lesson Figure 3: Student 2 Atom Before Lesson Figure 4: Student 2 Atom After Lesson Figure 5: Student 3 Atom Before Lesson Figure 6: Student 3 Atom After Lesson

8 References Baker, D. R., Pilburn, M. D. (1997). What do People Know About Physical Science? Constructing Science in Middle and Secondary School Classrooms (pp ). Boston, MA: Allyn and Bacon. Annonymous Interviewee, Personal Interview. October 16, 2012 and October 30, Annonymous Interviewee, Personal Interview. October 16, 2012 and October 30, Annonymous Interviewee, Personal Interview. October 16, 2012 and October 30, 2012.