The effect of temperature on atoms

1. Project 2061: Student Assessment The effect of temperature on atoms • Item format: • What happens to the [ ] of the atoms of a substance when the temperature is increased? • A.  The [ ] increases • B. The [ ] decreases • C.  The [ ] stays the same • where [ ] is • Distance between • Speed • Number • Size • Mass

2. Project 2061: Student Assessment % correct vs. grade • The % of “not sure” responses is higher for 6th grade. • Approximately 50% of 6th grade students were not familiar with atoms. • Student were taught atoms and molecules in 7th grade.

3. Project 2061: Student Assessment Student data for item about distance between atoms • Very few students believed that the distance would stay the same. • Misconception that distance decreases was well represented.

4. Project 2061: Student Assessment Student data for item about mass of atoms • Misconception that mass decreases with increasing temperature drops off with increasing grade. • 9th graders showed a preference for the mass increasing with increasing temperature.

5. Project 2061: Student Assessment Student data from pilot testing in 3 different school districts (grades 6-9) • The % “not sure” is significant for all items. • Students did the best on the speed item (45%). • Students did the worst on the mass item (23%). Student equally split between all answer choices. • Misconception that distance between atoms decreases with increasing temperature is held by a large %. • The misconceptions for number, size, and speed were all represented.

6. Project 2061: Student Assessment Connecting the macro-scale phenomenon with the molecular explanation Stem: After cooking breakfast, a cook places a hot iron frying pan on the counter to cool.  What happens as the iron pan cools? Answer Choices Version 1: A.  Even though you cannot see it, the pan gets a tiny bit smaller because the iron atoms decrease in size. B.  Even though you cannot see it, the pan gets a tiny bit smaller because the distance between iron atoms decreases. C.  Even though you cannot feel it, the pan gets a tiny bit heavier because the iron atoms increase in mass. D.  Even though you cannot feel it, the pan gets a tiny bit heavier because the number of iron atoms increases. Answer choices Version 2: A.  The iron atoms get heavier. B.  The iron atoms decrease in size. C.  The number of iron atoms increases. D.  The distance between iron atoms decreases.

7. Project 2061: Student Assessment Student data from pilot testing - (Grades 7-9) Version 1: Linking macro/molecular: 38 students Version 2: Molecular only: 31 students

8. Project 2061: Student Assessment Sample Student Responses to Version 1 answer choices • Answer choice A: No "Because if every time you cooked with an iron pan and the atoms got smaller in a couple of years you would not have an iron pan anymore would you." • Answer choice A: No "Because I don't think a pan can decrease its size without being broken." • Answer choice B: No "A pan cannot get smaller" • Answer choice B: No "No because the pan cannot get a tiny bit smaller." • Answer choice C: Not Sure "Its possible it could get heavier by atoms increase in mass but I'm not sure." • Answer choice D: Not Sure "This answer makes more sense after I eliminated the others"

9. Project 2061: Student Assessment Sample Student Responses to Version 2 answer choices • Answer choice A: No because “the iron atoms don’t get heavier when cooled down.” • Answer choice A: No because “atoms cannot increase in mass, or get ‘heavier’.” • Answer choice B: Yes “because they’re cooling so the size would decrease.” • Answer choice C: No because “temperature won’t create new molecules.” • Answer choice D: Yes “because since the temperature is cooling the iron atoms come closer together.” • Answer choice D: Yes because “the atoms slow down and get closer together.”

10. Project 2061: Student Assessment Expansion of a solid – Concrete sidewalks AM46-4 Most sidewalks made out of solid concrete have spaces between the sections as shown in the diagram below.  What happens to the width of the spaces during a hot day in the summer and why? A.  The spaces get wider because the concrete shrinks. B.  The spaces get narrower because the concrete expands. C.  The spaces stay the same because the concrete does not shrink or expand. D.  Some spaces get narrower and some get wider because some concrete expands and some concrete shrinks.

11. Project 2061: Student Assessment Student data from pilot testing (85 students, grades 7-9)

12. Project 2061: Student Assessment Sample student responses • Answer choice A: Yes, because “concrete expands when its cold” • Answer choice A: Yes, because “when it gets hot things shrink.” • Answer choice B: Yes, “the concrete and other objects expand when they are heated.” • Answer choice C: Yes because “concrete don’t move or do anything except break” • Answer choice C: Yes, “the concrete can't get wider or shrink because it is a solid" • Answer choice C: Yes because “concrete is a solid that is hard and can’t change shape.” • Answer choice D: No, because “concrete’s shape or size isn’t affected by heat.” • Answer choice D: Yes, “because it all depends on what concrete you use.” • Answer choice D: Yes, “because some concrete expand or shrink.” • Answer choice D: No, “because concrete can’t do both at the same time.” • Answer choice D: No, because “all the concrete has to do the same thing because it is the same substance under the same conditions.”

13. Project 2061: Student Assessment Movement of molecules In which of the following are the atoms or molecules NOT moving? A.  A solid wooden table B.  Liquid water in a glass C.  Air when there is no wind D.  All of the atoms or molecules of these materials are moving.

14. Project 2061: Student Assessment Student data from pilot testing – (38 students, grades 7-9)

15. Project 2061: Student Assessment Sample student responses • Answer choice A: Yes “because in a solid atoms have no room to move.” • Answer choice A: Yes “because it is solid and nothing can be inside it moving.” • Answer choice B: No “because atoms and molecules move through liquid water in a glass.” • Answer choice B: No because “molecules have more space to move around in and move faster.” • Answer choice C: No because “the air molecules move very freely.” • Answer choice C: No because “atoms in the air move even if there is no wind.” • Answer choice D: Yes because “all molecules move all the time.” • Answer choice D: No “because wood does not have molecules.”