Elementary School Science Quiz: Plan Investigations Mixing Substances
20 questions · exam conditions
0:00
Plan Investigations Mixing SubstancesQuestion 1 of 20

Students want to find out if mixing baking soda and vinegar makes something new. Their plan says: Purpose—watch for bubbles (gas) and temperature change. Materials—baking soda, vinegar, 2 clear cups, 1 tsp spoon, thermometer, tray, paper towels. Safety—Wear goggles, no tasting, wash hands after. Procedure: 1) Measure 2 tbsp vinegar into a cup and record its temperature. 2) Add 1 tsp baking soda and stir. 3) Record bubbles and temperature for 1 minute. What observation would provide the best evidence that a new substance formed?

Students should taste the mixture to see if it tastes different than vinegar.
Students should check whether bubbles form and whether the mixture gets cooler or warmer.
Students should decide the reaction happened because they predicted it would happen.
Students should only record the color of the vinegar before mixing.
← Back to quizzes

Elementary School Science Quiz

Elementary School Science Quiz: Plan Investigations Mixing Substances

Practice Plan Investigations Mixing Substances in Elementary School Science with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Plan Investigations Mixing Substances, giving you a quick way to practice the rules, question types, and explanations that matter most for Elementary School Science.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

All questions

Question 1

Students want to find out if mixing baking soda and vinegar makes something new. Their plan says: Purpose—watch for bubbles (gas) and temperature change. Materials—baking soda, vinegar, 2 clear cups, 1 tsp spoon, thermometer, tray, paper towels. Safety—Wear goggles, no tasting, wash hands after. Procedure: 1) Measure 2 tbsp vinegar into a cup and record its temperature. 2) Add 1 tsp baking soda and stir. 3) Record bubbles and temperature for 1 minute. What observation would provide the best evidence that a new substance formed?

  1. Students should taste the mixture to see if it tastes different than vinegar.
  2. Students should check whether bubbles form and whether the mixture gets cooler or warmer. (correct answer)
  3. Students should decide the reaction happened because they predicted it would happen.
  4. Students should only record the color of the vinegar before mixing.
Explanation: This question tests a 5th grader's ability to plan and carry out investigations that mix substances (NGSS 5-PS1-4), specifically observations. When planning a mixing investigation, students need to observe before and after to detect changes like gas production or temperature shifts that indicate a new substance. For this question, investigating whether baking soda and vinegar create new substance. Choice B is correct because it recognizes the need to observe bubbles and temperature changes. This shows the student understands before/after comparison shows change. Choice A represents a common error where students suggest tasting to observe, skipping safety rules. This typically happens because elementary students may prioritize excitement of mixing over safety. To help students: Use investigation checklist (question-materials-safety-procedure-recording). Watch for: Students who underestimate importance of safety rules.

Question 2

Students want to find out if mixing baking soda and vinegar creates a new substance. Amir's plan says: Purpose—see what happens when 1 tbsp baking soda is mixed with 30 mL vinegar in a clear cup. Safety—wear goggles, no tasting, and work on a tray. Procedure—(1) Observe each substance before mixing. (2) Mix and watch for bubbles and temperature change. (3) Record observations in a data table and clean up. Which observation would provide the best evidence that a new substance formed?

  1. Students should record that the vinegar smells sour before mixing and still smells sour after mixing.
  2. Students should record that bubbles of gas form right after mixing and the mixture gets foamy. (correct answer)
  3. Students should record that the baking soda is a white powder before mixing.
  4. Students should record that the cup is clear so they can see the mixture.
Explanation: This question tests 5th grader's ability to plan and carry out investigations that mix substances (NGSS 5-PS1-4), specifically identifying observations that provide evidence of chemical change. When planning a mixing investigation, students need to recognize that new substances form when we observe signs like gas production, temperature change, color change, or precipitate formation. For this question, mixing baking soda and vinegar creates carbon dioxide gas, which appears as bubbles and foam. Choice B is correct because it identifies the key observable evidence of a chemical reaction - the formation of gas bubbles and foam that weren't present in either original substance. This shows the student understands that new substances have different properties than the starting materials. Choice A represents a common error where students focus on properties that don't change (the vinegar still smells sour) rather than looking for new properties that appear. This typically happens because elementary students may not yet distinguish between physical properties that persist and new properties that indicate chemical change. To help students: Model identifying evidence of chemical change by having them list properties before and after mixing, then circle any NEW properties that appear. Watch for: Students who think any observation counts as evidence rather than focusing on changes that indicate new substance formation.

Question 3

To investigate whether mixing creates a new substance, Maya mixes yeast, sugar, and warm water. Her steps are: 1) Mix 1 tsp yeast, 1 tsp sugar, and 1/2 cup warm water in a clear cup. 2) Watch for 10 minutes. 3) Write down what happens. What should Maya do first to make her investigation plan stronger?

  1. She should clean up all materials first so the table is empty.
  2. She should observe and record what each substance looks like before mixing. (correct answer)
  3. She should add random extra sugar each minute to speed up changes.
  4. She should taste the mixture to check if it is still sweet.
Explanation: This question tests a 5th grader's ability to plan and carry out investigations that mix substances (NGSS 5-PS1-4), specifically the procedure for baseline observations. When planning a mixing investigation, students need to include clear questions, gather appropriate materials, follow safety rules, observe before and after, and record systematically. For this question, the specific context is investigating whether mixing yeast, sugar, and water creates a new substance through changes like bubbling. Choice B is correct because it follows a logical order of observe-mix-observe-record by starting with recording appearances before mixing for comparison. This shows the student understands that before/after comparison shows change and provides evidence of reactions. Choice D represents a common error where students suggest tasting the mixture to check properties like sweetness, skipping safety precautions. This typically happens because elementary students may prioritize excitement of mixing over safety and not yet understand that tasting can introduce risks or bias observations. To help students: Model planning with simple investigations like sugar in water before complex ones, emphasizing the step of 'observe before mixing' to establish a baseline. Watch for: Students who jump to mixing without planning, as they might forget to record initial states and lose the ability to compare changes.

Question 4

Emma's notebook entry says: Question—"What happens when we mix 1 tbsp baking soda with 30 mL lemon juice?" Prediction—"I think it will get fizzy." Procedure: 1) Mix the substances in a cup. 2) Clean up the table. 3) Record what happened. Which step should come right after mixing the substances to follow a good procedure order?

  1. Clean up immediately so nothing spills, and then decide what happened.
  2. Observe and record changes like bubbles and temperature before cleaning up. (correct answer)
  3. Put the cup away without looking so the reaction can finish in private.
  4. Add more lemon juice each minute until the cup is full.
Explanation: This question tests a 5th grader's ability to plan and carry out investigations that mix substances (NGSS 5-PS1-4), specifically the logical order in procedures. When planning a mixing investigation, students need to include clear questions, gather appropriate materials, follow safety rules, observe before and after, and record systematically. For this question, the specific context is investigating what happens when mixing baking soda and lemon juice. Choice B is correct because it follows a logical order of observe-mix-observe-record by noting changes like bubbles and temperature right after mixing. This shows the student understands that before/after comparison shows change and recording should happen before cleanup. Choice A represents a common error where students clean up first, potentially missing key observations during the reaction. This typically happens because elementary students may prioritize tidiness over systematic observation, thinking they can remember without immediate recording. To help students: Model planning with a checklist for procedure order, like mix-observe-record-clean, using examples like fizzy reactions. Watch for: Students who try to conclude before observing fully, jumping to cleanup and losing evidence of changes.

Question 5

The investigation plan shows Chen comparing two mixtures: Cup 1 has 1 tsp baking soda + 2 tbsp vinegar. Cup 2 has 1 tsp baking soda + 2 tbsp water. Students will count bubbles for 30 seconds. Why is Cup 2 included?

  1. Cup 2 is included so students can practice stirring before the real test.
  2. Cup 2 is included to show what happens when baking soda is mixed with water only. (correct answer)
  3. Cup 2 is included so students can taste it safely after the investigation.
  4. Cup 2 is included to make sure both cups have different amounts of baking soda.
Explanation: This question tests a 5th grader's ability to plan and carry out investigations that mix substances (NGSS 5-PS1-4), specifically procedure. When planning a mixing investigation, students need to include controls for fair tests. For this question, comparing baking soda with vinegar vs water. Choice B is correct because it follows logical order of observe-mix-observe-record with a control cup. This shows the student understands proper materials enable observations. Choice C represents a common error where students include tasting, ignoring safety. This typically happens because elementary students may not connect materials to specific observations needed. To help students: Practice identifying what makes a good testable question. Watch for: Students who think conclusion should match prediction.

Question 6

The investigation plan shows Fatima testing food coloring in water. Procedure: 1) Put 1/2 cup water into a clear cup. 2) Add 2 drops of food coloring. 3) Observe for 2 minutes and record changes. If Fatima wants to repeat the test to be sure of her results, what should she keep the same each time?

  1. She should keep the amount of water and number of drops the same each trial. (correct answer)
  2. She should change the amount of water each time to get more interesting results.
  3. She should switch to a different cup size every time and not measure.
  4. She should record only the final color and skip observing during mixing.
Explanation: This question tests a 5th grader's ability to plan and carry out investigations that mix substances (NGSS 5-PS1-4), specifically procedure. When planning a mixing investigation, students need to keep variables constant for repeatability. For this question, investigating food coloring diffusion in water. Choice A is correct because it includes keeping amounts the same for fair comparison. This shows the student understands investigations need clear purpose. Choice B represents a common error where students change variables randomly. This typically happens because elementary students may not yet understand importance of baseline observations. To help students: Model planning with simple investigation like sugar in water before complex ones. Watch for: Students who observe but don't record systematically.

Question 7

Keisha is mixing cabbage juice (purple) with other substances to see color changes. Her plan says: "Put 2 tbsp cabbage juice in two cups. Add 1 tbsp vinegar to Cup 1 and 1 tsp baking soda mixed with 1 tbsp water to Cup 2. Observe." How should Keisha record her observations so she can compare results clearly?

  1. Keisha should only remember the colors in her head and share them later.
  2. Keisha should write a data table with 'Before Mixing,' 'During Mixing,' and 'After Mixing' for each cup. (correct answer)
  3. Keisha should clean up right after mixing so the colors do not change.
  4. Keisha should taste each cup to decide which one is more acidic.
Explanation: This question tests 5th grader's ability to plan and carry out investigations that mix substances (NGSS 5-PS1-4), specifically creating organized recording systems for observations. When planning a mixing investigation, students need to create data tables or recording sheets that capture observations at key time points - this allows for clear comparisons and prevents forgetting important details. For this question, Keisha needs to track color changes in multiple cups over time. Choice B is correct because it describes a systematic data table with columns for different time points ('Before Mixing,' 'During Mixing,' 'After Mixing') for each cup, enabling clear comparison of how each substance affects cabbage juice color. This shows the student understands that organized recording systems are essential for tracking multiple trials. Choice A represents a common error where students rely on memory rather than written records. This typically happens because elementary students often overestimate their ability to remember details and may not yet value systematic documentation. To help students: Provide data table templates for investigations and model filling them out in real-time, showing how tables help us see patterns across multiple trials. Watch for: Students who think they can remember everything or who create disorganized notes that make comparison difficult later.

Question 8

The investigation plan shows Maya mixing 1 tbsp salt with 1/2 cup water to see how fast salt dissolves. Materials listed: salt, water, 3 clear cups, 1 tsp spoon, timer, tray. Safety: No tasting and wash hands. Procedure: 1) Put 1/2 cup water in each cup. 2) Add 1 tbsp salt and stir 10 times. 3) Write what you see after 30 seconds. What is missing that would make this a fair test for "how fast" the salt dissolves?

  1. Students should use a different amount of water in each cup to compare more results.
  2. Students should taste the water to check if the salt is still there.
  3. Students should record the time it takes until the salt is no longer visible in each cup. (correct answer)
  4. Students should use a magnifying glass to look at the salt grains up close.
Explanation: This question tests a 5th grader's ability to plan and carry out investigations that mix substances (NGSS 5-PS1-4), specifically procedure. When planning a mixing investigation, students need to follow logical order of observe-mix-observe-record. For this question, comparing salt dissolving. Choice C is correct because it includes recording time for dissolving, making it a fair test for speed. This shows the student understands proper procedure enables observations. Choice B represents a common error where students suggest tasting to check, forgetting safety. This typically happens because elementary students may not yet understand importance of baseline observations. To help students: Model planning with simple investigation like sugar in water before complex ones. Watch for: Students who observe but don't record systematically.

Question 9

Chen is planning an investigation: "What happens when I mix sand and water?" Materials: sand, water, 2 clear cups, 1 tsp measuring spoon. Procedure: (1) Put 1 tsp sand in a cup. (2) Add 1/2 cup water and stir. (3) Watch for 3 minutes. What is missing from Chen's plan that would make the investigation better?

  1. Chen should add food coloring so the water turns a brighter color.
  2. Chen should record observations before, during, and after mixing in writing or a table. (correct answer)
  3. Chen should taste the sand-water mixture to see if it is salty.
  4. Chen should use a different amount of sand each time to make it more exciting.
Explanation: This question tests 5th grader's ability to plan and carry out investigations that mix substances (NGSS 5-PS1-4), specifically the importance of systematic observation and recording. When planning a mixing investigation, students need to document what they observe at each stage - before mixing (baseline), during mixing (process), and after mixing (results) - to track changes and draw conclusions. For this question, Chen's procedure observes the mixing but lacks any recording system. Choice B is correct because it identifies the critical missing element: a system for recording observations at multiple time points, either through written notes or a data table. This shows the student understands that science requires documentation, not just watching. Choice C represents a common error where students suggest tasting the mixture, violating basic safety rules. This typically happens because elementary students may default to using all their senses without considering safety restrictions in scientific investigations. To help students: Provide observation templates with columns for 'Before,' 'During,' and 'After' to scaffold systematic recording, and model how to describe observations using scientific vocabulary. Watch for: Students who think they can remember everything without writing it down or who only record final results without documenting the process.

Question 10

To investigate whether mixing oil and water makes a mixture that stays mixed, Carlos wrote this procedure: 1) Pour 1/2 cup water into a clear jar. 2) Add 2 tbsp oil and put the lid on tightly. 3) Shake for 10 seconds and observe. Which measurement should Carlos record to best answer his question?

  1. How long it takes for the oil and water to separate into two layers after shaking. (correct answer)
  2. How many times he can shake the jar before his arms get tired.
  3. What the oil tastes like compared to the water.
  4. Whether the jar is made of glass or plastic.
Explanation: This question tests a 5th grader's ability to plan and carry out investigations that mix substances (NGSS 5-PS1-4), specifically recording. When planning a mixing investigation, students need to record systematically. For this question, investigating whether oil and water stay mixed. Choice A is correct because it follows logical order of observe-mix-observe-record by measuring separation time. This shows the student understands recording creates evidence. Choice C represents a common error where students suggest tasting, ignoring safety. This typically happens because elementary students may prioritize excitement of mixing over safety. To help students: Emphasize that science is observing what actually happens, not proving we're right. Watch for: Students who think conclusion should match prediction.

Question 11

The investigation plan shows Jamal testing cabbage juice (purple) with vinegar and with baking soda water. Safety notes include: Wear goggles, no tasting, and clean spills. Procedure: 1) Pour 2 tbsp cabbage juice into two clear cups. 2) Add 1 tsp vinegar to Cup A and 1 tsp baking soda water to Cup B. 3) Observe and record color changes. Why are clear cups important for this investigation?

  1. Clear cups help students see any color change in the liquids right away. (correct answer)
  2. Clear cups make the mixtures taste better than using colored cups.
  3. Clear cups keep the temperature the same better than any other cup.
  4. Clear cups make the cabbage juice turn purple even before anything is added.
Explanation: This question tests a 5th grader's ability to plan and carry out investigations that mix substances (NGSS 5-PS1-4), specifically materials. When planning a mixing investigation, students need to gather appropriate materials. For this question, investigating color changes with cabbage juice. Choice A is correct because it includes all necessary materials like clear cups for observing changes. This shows the student understands proper materials enable observations. Choice B represents a common error where students include unnecessary tasting ideas, missing safety. This typically happens because elementary students may not yet understand importance of baseline observations. To help students: Use investigation checklist (question-materials-safety-procedure-recording). Watch for: Students who underestimate importance of safety rules.

Question 12

Chen wants a fair test to compare how fast sugar dissolves in cold water versus warm water. He plans to use two clear cups, 1/2 cup water in each, and 1 tsp sugar in each. Which action best keeps the test fair?

  1. Use different cup sizes so one cup has more room for the sugar.
  2. Stir the warm water cup for 60 seconds and the cold water cup for 10 seconds.
  3. Keep the amount of sugar and the amount of water the same in both cups. (correct answer)
  4. Add food coloring to only one cup so it is easier to see.
Explanation: This question tests a 5th grader's ability to plan and carry out investigations that mix substances (NGSS 5-PS1-4), specifically fair testing in procedures. When planning a mixing investigation, students need to include clear questions, gather appropriate materials, follow safety rules, observe before and after, and record systematically. For this question, the specific context is comparing sugar dissolving in cold versus warm water. Choice C is correct because it keeps variables like amounts of sugar and water the same, ensuring a fair comparison of temperature's effect. This shows the student understands that proper materials and consistent procedures enable accurate observations of differences. Choice B represents a common error where students vary stirring times, making the test unfair by changing multiple factors. This typically happens because elementary students may not yet understand the importance of controlling variables, thinking more stirring always helps without considering fairness. To help students: Practice identifying what makes a good testable question and model fair tests with checklists for 'what stays the same' versus 'what changes.' Watch for: Students who think conclusion should match prediction, adjusting procedures unfairly to 'prove' they're right.

Question 13

Students want to find out how food coloring spreads in water. Their procedure is: 1) Put 1/2 cup water in a clear cup. 2) Add 2 drops of food coloring. 3) Observe for 2 minutes and record changes. Which measurement should students record to make their observations more accurate and consistent?

  1. Record the time (in seconds) it takes for the color to spread across the cup. (correct answer)
  2. Record how much students like the color, using smiley faces only.
  3. Record the teacher's favorite drink, because it affects spreading.
  4. Record the brand of the cup, because only certain cups show color.
Explanation: This question tests a 5th grader's ability to plan and carry out investigations that mix substances (NGSS 5-PS1-4), specifically accurate and consistent observations. When planning a mixing investigation, students need to include clear questions, gather appropriate materials, follow safety rules, observe before and after, and record systematically. For this question, the specific context is investigating how food coloring spreads in water. Choice A is correct because it measures time for color spreading, providing quantifiable data for consistency. This shows the student understands that recording creates evidence through measurable changes like time. Choice B represents a common error where students record opinions like liking the color with smiley faces, confusing subjective feelings with objective observations. This typically happens because elementary students may think personal preferences are part of science, not yet distinguishing between facts and opinions. To help students: Model planning with simple investigations like food coloring in water, using timers to practice measuring changes. Watch for: Students who think conclusion should match prediction, recording only what supports their guess instead of actual times.

Question 14

To investigate whether mixing baking soda and lemon juice causes a change, Amir wrote: Materials—baking soda, lemon juice, cup, spoon. Procedure: 1) Pour lemon juice into the cup. 2) Add baking soda. 3) Watch what happens. Which safety rule is most important to add for this investigation?

  1. Wear goggles because the mixture can fizz and splash into eyes. (correct answer)
  2. Taste the mixture right away so you can tell if it changed.
  3. Hold the cup close to your face to smell it better.
  4. Use the biggest cup you can find so you do not need to measure.
Explanation: This question tests a 5th grader's ability to plan and carry out investigations that mix substances (NGSS 5-PS1-4), specifically safety. When planning a mixing investigation, students need to follow safety rules. For this question, investigating baking soda and lemon juice reaction. Choice A is correct because it includes safety equipment like goggles for fizzing. This shows the student understands safety prevents harm. Choice B represents a common error where students suggest tasting, skipping safety. This typically happens because elementary students may prioritize excitement of mixing over safety. To help students: Emphasize that science is observing what actually happens, not proving we're right. Watch for: Students who underestimate importance of safety rules.

Question 15

The investigation plan shows Sofia mixing 1 tsp sugar into 1/2 cup water to see if the sugar dissolves. Safety rules include washing hands and no tasting. Which step should Sofia do first to make good observations?

  1. Stir the sugar and water quickly, then decide what happened without writing anything down.
  2. Observe and record what the sugar and water look like before mixing them together. (correct answer)
  3. Clean up the cups and put materials away before mixing.
  4. Add more and more sugar until the water turns into a thick paste.
Explanation: This question tests a 5th grader's ability to plan and carry out investigations that mix substances (NGSS 5-PS1-4), specifically procedure. When planning a mixing investigation, students need to follow safety rules and observe before and after. For this question, investigating whether sugar dissolves in water. Choice B is correct because it follows logical order of observe-mix-observe-record starting with before observations. This shows the student understands before/after comparison shows change. Choice A represents a common error where students forget to record, thinking they can remember. This typically happens because elementary students may not yet understand importance of baseline observations. To help students: Use investigation checklist (question-materials-safety-procedure-recording). Watch for: Students who jump to mixing without planning.

Question 16

The materials list includes vinegar, baking soda, a clear cup, a tray, a thermometer, and goggles. Students will pour 30 mL vinegar into the cup and add 1 tbsp baking soda. Which safety rule is most important for this investigation?

  1. Wear goggles, because the mixture can bubble and splash into eyes. (correct answer)
  2. Turn off the classroom lights, because reactions only happen in the dark.
  3. Taste the mixture to check if it is safe, because vinegar is food.
  4. Hold the cup near your face, because it is easier to see the bubbles.
Explanation: This question tests a 5th grader's ability to plan and carry out investigations that mix substances (NGSS 5-PS1-4), specifically safety precautions. When planning a mixing investigation, students need to include clear questions, gather appropriate materials, follow safety rules, observe before and after, and record systematically. For this question, the specific context is investigating baking soda and vinegar, which can produce bubbling reactions. Choice A is correct because it includes safety equipment like goggles to protect eyes from splashes during bubbling. This shows the student understands that safety prevents harm in reactions that might fizz or splash. Choice C represents a common error where students suggest tasting because ingredients like vinegar are food-related, ignoring potential risks. This typically happens because elementary students may underestimate importance of safety rules and think familiar items are always safe to taste. To help students: Use an investigation checklist that highlights safety first, and demonstrate why goggles are needed with a safe demo of bubbling. Watch for: Students who prioritize excitement of mixing over safety, such as holding cups too close without protection.

Question 17

Students want to find out what happens when sand is mixed with water. Their plan includes a data table with columns "Before Mixing," "During Mixing," and "After Mixing." What should they record in the "Before Mixing" column?

  1. Only their final conclusion about whether the sand dissolved.
  2. What the sand and water look like separately, including color and texture. (correct answer)
  3. How the sand and water look after they have been sitting for 10 minutes.
  4. How many times they stirred, but not what the substances look like.
Explanation: This question tests a 5th grader's ability to plan and carry out investigations that mix substances (NGSS 5-PS1-4), specifically recording. When planning a mixing investigation, students need to record systematically. For this question, comparing sand settling. Choice B is correct because it recognizes need to observe color and texture before mixing. This shows the student understands before/after comparison shows change. Choice A represents a common error where students skip to conclusion without observations. This typically happens because elementary students may think they can remember without recording. To help students: Model planning with simple investigation like sugar in water before complex ones. Watch for: Students who observe but don't record systematically.

Question 18

The materials list includes: warm water (about 40°C), yeast, sugar, 3 small bottles, balloons, 1 tsp spoon, and a tray. Students want to find out: "Does adding sugar change how much gas yeast makes?" Which setup best matches this question?

  1. Put yeast and warm water in all bottles, and add sugar to only one bottle. (correct answer)
  2. Put sugar and warm water in all bottles, and add yeast to only one bottle.
  3. Put different amounts of yeast and different amounts of sugar in every bottle.
  4. Put only warm water in all bottles, then put balloons on and wait.
Explanation: This question tests a 5th grader's ability to plan and carry out investigations that mix substances (NGSS 5-PS1-4), specifically purpose. When planning a mixing investigation, students need to include clear question. For this question, investigating whether adding sugar changes gas from yeast. Choice A is correct because it identifies the clear testable question by varying sugar while keeping yeast constant. This shows the student understands investigations need clear purpose. Choice C represents a common error where students vary everything, missing controlled variables. This typically happens because elementary students may not connect materials to specific observations needed. To help students: Practice identifying what makes a good testable question. Watch for: Students who jump to mixing without planning.

Question 19

Students want to find out whether oil and water mix together. Jamal sets up three cups: Cup 1 has 1/2 cup water only, Cup 2 has 1/2 cup oil only, and Cup 3 has 1/2 cup water + 1/2 cup oil. Why is Cup 1 (water only) helpful in this investigation?

  1. It is a comparison cup, so students can see what water looks like without oil mixed in. (correct answer)
  2. It makes the oil disappear faster because water pulls oil down.
  3. It is needed so students can taste the water and compare it to oil.
  4. It is used to make the mixture warmer because plain water heats itself.
Explanation: This question tests a 5th grader's ability to plan and carry out investigations that mix substances (NGSS 5-PS1-4), specifically the purpose of control setups in comparisons. When planning a mixing investigation, students need to include clear questions, gather appropriate materials, follow safety rules, observe before and after, and record systematically. For this question, the specific context is investigating whether oil and water mix, using separate cups for comparison. Choice A is correct because it identifies Cup 1 as a comparison cup, allowing students to see water's appearance without oil for baseline observations. This shows the student understands that before/after comparison shows change and helps determine if mixing occurred. Choice C represents a common error where students suggest tasting to compare, overlooking safety and the focus on visual mixing. This typically happens because elementary students may not connect materials to specific observations needed, like sight for separation, and might default to taste from everyday experiences. To help students: Practice identifying what makes a good testable question and model setups with controls, like plain water versus mixed, to emphasize comparisons. Watch for: Students who underestimate importance of safety rules, such as no tasting, and try unsafe methods to 'prove' results.

Question 20

The investigation plan shows Fatima mixing sand and water to see if sand dissolves. She will use 1/2 cup water and 2 tbsp sand in a clear jar. Which data table header set would best help Fatima record observations in an organized way?

  1. "Best Friend" / "Favorite Color" / "Snack Choice"
  2. "Before Mixing" / "During Mixing" / "After Mixing" (correct answer)
  3. "Monday" / "Tuesday" / "Wednesday"
  4. "Tall" / "Taller" / "Tallest"
Explanation: This question tests a 5th grader's ability to plan and carry out investigations that mix substances (NGSS 5-PS1-4), specifically recording observations in an organized way. When planning a mixing investigation, students need to include clear questions, gather appropriate materials, follow safety rules, observe before and after, and record systematically. For this question, the specific context is investigating whether sand dissolves in water, focusing on data table organization. Choice B is correct because it uses headers like Before, During, and After Mixing to structure observations chronologically. This shows the student understands that recording creates evidence and helps track changes over time. Choice A represents a common error where students include unrelated personal details like favorite color, missing the focus on scientific observations. This typically happens because elementary students may not connect materials to specific observations needed, blending science with everyday interests. To help students: Emphasize that science is observing what actually happens, not proving we're right, and provide template data tables for mixes like sand in water. Watch for: Students who observe but don't record systematically, such as jotting random notes without structure.