Students will need about minutes to complete this brief constructed response.

Transcription

1 Prompt 1 Objectives assessed: The student will be able to: Explain the difference between a physical and chemical change. Explain that in a chemical reaction energy is absorbed or released. Explain that in a chemical reaction, molecules separate and combine to form new compounds. Explain that during a chemical reaction, the total mass of the reactants equals the total mass of the resulting substances. Describe exothermic reactions as reactions that give off energy. Describe endothermic reactions as reactions that absorb energy. Students will need about minutes to complete this brief constructed response. Iron with 20% saltwater Nathan and Marta are doing an experiment to determine the effect of different types of water on the rusting of iron. They decide to use tap water, a 10% saltwater solution, and a 20% saltwater solution. In order to make the saltwater solutions they must dissolve salt into the water. They added a piece of iron to each of the water mixtures for one week and made sure the system was closed so that no water could escape. They didn t add anything else to the iron. The picture above is how they found the iron that was treated with the 20% saltwater solution. Observations that were made during the experiment are listed to the right of the picture. Where did a physical change occur and where did a chemical change occur and explain how you know? Brief Constructed Response: 2010 Discovery Education Page 1 of 6

2 Correct response(s): Sample Correct Response: A physical change occurs when the students dissolve the salt in the water. This is a physical change because the saltwater mixture can be separated into salt and water again. The appearance changes, but not the chemical composition. A chemical change occurs when the rust forms. This is a chemical change because the rust is a new substance that can not be changed back into iron. Rust has new properties with a new chemical composition. Response scoring tool: Score Content 3 Response identifies; Physical change- occurred when salt was dissolved in water; student knows this because- dissolving is a physical change, the salt and water can be separated, the appearance changes not the chemical make up; Chemical change- occurs when the iron rusts; student knows this because- rusting is a chemical change, the new red substance can not be changed back into water or iron, new properties are formed, the chemical composition has changed 2 Response identifies; Physical change- occurred when salt was dissolved in water; student knows this because- dissolving is a physical change, the appearance changes not the chemical make up; Chemical changeoccurs when the iron rusts; student knows this because- rusting is a chemical change, the chemical composition has changed 1 Response identifies; Physical change- occurred when salt was dissolved in water; student knows this because- dissolving is a physical change, Chemical change- occurs when the iron rusts; student knows this because- rusting is a chemical change 0 No response, or response not appropriate to the question. Teacher Notes: The scenario provided above is used for all three prompts. On the student version, page 1 contains the scenario, page 2 contains prompt 1, page 3 contains prompt 2, and page 4 contains prompt 3. Brief Constructed Response: 2010 Discovery Education Page 2 of 6

3 Prompt 2 Objectives assessed: The student will be able to: Explain the difference between a physical and chemical change. Explain that in a chemical reaction energy is absorbed or released. Explain that in a chemical reaction, molecules separate and combine to form new compounds. Explain that during a chemical reaction, the total mass of the reactants equals the total mass of the resulting substances. Describe exothermic reactions as reactions that give off energy. Describe endothermic reactions as reactions that absorb energy. Students will need about minutes to complete this brief constructed response. Iron with 20% saltwater Nathan and Marta are doing an experiment to determine the effect of different types of water on the rusting of iron. They decide to use tap water, a 10% saltwater solution, and a 20% saltwater solution. In order to make the saltwater solutions they must dissolve salt into the water. They added a piece of iron to each of the water mixtures for one week and made sure the system was closed so that no water could escape. They didn t add anything else to the iron. The picture above is how they found the iron that was treated with the 20% saltwater solution. Observations that were made during the experiment are listed to the right of the picture. Identify were an exothermic reaction and an endothermic reaction occurred and explain how you know? Brief Constructed Response: 2010 Discovery Education Page 3 of 6

4 Correct response(s): Sample Correct Response: An exothermic reaction occurred where the rust formed. Exothermic reactions give off heat. The students noted in their observations that there was an increase in temperature where the rust was forming. An endothermic reaction occurred when the students added the salt to the water. Endothermic reactions absorb heat. The students noted in their observations that there was a decrease in temperature when they added the salt to the water. Response scoring tool: Score Content 3 Response identifies; Exothermic- occurred when rust formed, exothermic reactions give off heat, temperature increased when the rust formed. Endothermic- occurred when salt was mixed with water, endothermic reactions absorb heat, students noted a decrease in temperature when the salt was mixed with water 2 Response identifies; Exothermic- occurred when rust formed, exothermic reactions give off heat, Endothermic- occurred when salt was mixed with water, endothermic reactions absorb heat 1 Response identifies; Exothermic- occurred when rust formed; Endothermic- occurred when salt was mixed with water 0 No response, or response not appropriate to the question. Teacher Notes: The scenario provided above is used for all three prompts. On the student version, page 1 contains the scenario, page 2 contains prompt 1, page 3 contains prompt 2, and page 4 contains prompt 3. Brief Constructed Response: 2010 Discovery Education Page 4 of 6

5 Prompt 3 Objectives assessed: The student will be able to: Explain the difference between a physical and chemical change. Explain that in a chemical reaction energy is absorbed or released. Explain that in a chemical reaction, molecules separate and combine to form new compounds. Explain that during a chemical reaction, the total mass of the reactants equals the total mass of the resulting substances. Describe exothermic reactions as reactions that give off energy. Describe endothermic reactions as reactions that absorb energy. Students will need about minutes to complete this brief constructed response. Iron with 20% saltwater Nathan and Marta are doing an experiment to determine the effect of different types of water on the rusting of iron. They decide to use tap water, a 10% saltwater solution, and a 20% saltwater solution. In order to make the saltwater solutions they must dissolve salt into the water. They added a piece of iron to each of the water mixtures for one week and made sure the system was closed so that no water could escape. They didn t add anything else to the iron. The picture above is how they found the iron that was treated with the 20% saltwater solution. Observations that were made during the experiment are listed to the right of the picture. Define the Law of Conservation of mass and explain if it was obeyed during this experiment. Provide evidence to support your answer. Brief Constructed Response: 2010 Discovery Education Page 5 of 6

6 Correct response(s): Sample Correct Response: The Law of Conservation of Mass states that mass can not be gained or lost during a physical or chemical reaction. The Law of Conservation of mass was obeyed in this experiment because the mass of the water and iron before the reaction is equal to the mass of the objects after the reaction. Response scoring tool: Score Content 3 Response identifies; Law of Conservation of Mass- mass can not be gained or lost during a physical or chemical reaction; Law of Conservation of Mass was obeyed, the mass of the substances before the reaction is the same as the mass of the reactants after the reaction. 2 Response identifies; Law of Conservation of Mass- mass can not be gained or lost during a physical or chemical reaction; Law of Conservation of Mass was obeyed, 1 Response identifies; Law of Conservation of Mass- mass can not be gained or lost during a physical or chemical reaction or states Law of Conservation of Mass was obeyed, the mass of the substances before the reaction is the same as the mass of the reactants after the reaction. 0 No response, or response not appropriate to the question. Teacher Notes: The scenario provided above is used for all three prompts. On the student version, page 1 contains the scenario, page 2 contains prompt 1, page 3 contains prompt 2, and page 4 contains prompt 3. Brief Constructed Response: 2010 Discovery Education Page 6 of 6