All flashcards
Flashcard 1: What are controlled variables (constants) in a mixing investigation?
Answer: Factors kept the same for a fair test. Keeping them constant ensures only one variable affects results.
Flashcard 2: What is the correct safety action if a chemical or mixture splashes into your eyes?
Answer: Rinse with water and tell an adult immediately. Quick action prevents serious eye damage from chemicals.
Flashcard 3: What is the correct safety rule for tasting substances during mixing investigations?
Answer: Never taste any lab substance. Lab substances may be toxic or harmful if ingested.
Flashcard 4: Which tool is most appropriate to measure mass of a solid to be mixed: thermometer, balance, or stopwatch?
Answer: Balance. It accurately measures mass in grams for precise mixing.
Flashcard 5: Which tool is most appropriate to measure liquid volume for mixing: ruler, balance, or graduated cylinder?
Answer: Graduated cylinder. It precisely measures liquid volumes in milliliters.
Flashcard 6: What is the purpose of repeating trials in a mixing investigation?
Answer: To increase reliability of results. Multiple trials help confirm results aren't due to chance.
Flashcard 7: What is a fair test when comparing how two solids dissolve in water?
Answer: Change only the solid; keep all else constant. This isolates the solid type as the only variable affecting results.
Flashcard 8: Which question best tests how mixing affects dissolving: color, size, or stirring speed?
Answer: Stirring speed. Stirring directly affects how substances mix and dissolve.
Flashcard 9: Which variable should be controlled when testing how stirring affects dissolving?
Answer: Temperature (keep it the same). Temperature affects dissolving rate, so it must stay constant.
Flashcard 10: Identify the dependent variable: you time how long sugar takes to dissolve when stirred at different speeds.
Answer: Time to dissolve. You're measuring how stirring speed affects this outcome.
Flashcard 11: Find the independent variable: you test 5g, 10g, and 15g of salt in 100mL water.
Answer: Mass of salt added. You're changing the amount to test its effect.
Flashcard 12: Identify the control group in this test: add sugar to cold water vs hot water to compare dissolving.
Answer: Cold water (baseline condition). Control groups show results without the tested change.
Flashcard 13: Which safety step is most important before mixing unknown liquids in class?
Answer: Wear goggles and follow teacher instructions. Safety equipment and supervision prevent accidents.
Flashcard 14: Which observation best shows that a solid has dissolved in water?
Answer: The mixture looks uniform with no visible particles. Complete dissolving creates a clear, transparent solution.
Flashcard 15: What is a solvent in a solution made by mixing substances?
Answer: The substance that does the dissolving. Usually the liquid, like water dissolving salt.
Flashcard 16: What is a solute in a solution made by mixing substances?
Answer: The substance that dissolves. Like salt or sugar that disappears into water.
Flashcard 17: What is the best unit choice for mass in a classroom mixing investigation?
Answer: Grams (g). Standard metric unit for small masses.
Flashcard 18: What is the best unit choice for liquid volume in a classroom mixing investigation?
Answer: Milliliters (mL). Standard metric unit for small liquid volumes.
Flashcard 19: Identify the correct tool to measure mass of a substance before mixing.
Answer: Balance (scale). It precisely measures weight in grams or other units.
Flashcard 20: Identify the correct tool to measure liquid volume accurately in a mixing test.
Answer: Graduated cylinder. It has precise volume markings for accurate measurement.
Flashcard 21: What should you include in a procedure so another student can repeat your mixing test?
Answer: Clear step-by-step directions with exact amounts and times. Specific details ensure reproducible results.
Flashcard 22: What is one appropriate way to record results while mixing substances?
Answer: Use a labeled data table with units. Tables organize data clearly with proper measurements.
Flashcard 23: What is the purpose of repeating trials in a mixing investigation?
Answer: To improve reliability by reducing random error. Multiple trials help identify and minimize measurement errors.
Flashcard 24: What are controlled variables in an investigation that mixes substances?
Answer: Factors kept the same to make a fair test. Controlling variables ensures only one factor affects results.
Flashcard 25: Find the independent variable: You test how stirring time affects how fast sugar dissolves.
Answer: Stirring time. You're changing stirring time to test its effect.
Flashcard 26: Find the dependent variable: You test how water temperature affects how fast salt dissolves.
Answer: Time (rate) for salt to dissolve. You're measuring how temperature affects dissolving rate.
Flashcard 27: Identify the control group: Plant A gets water only; Plant B gets water mixed with fertilizer.
Answer: Plant A (water only). It receives no treatment, serving as a comparison baseline.
Flashcard 28: Choose the best safety rule for mixing unknown substances in class.
Answer: Wear goggles and follow teacher directions; do not taste or smell directly. These precautions prevent injury from unknown chemical reactions.
Flashcard 29: Which tool is most appropriate to measure liquid volume accurately in a mixing investigation?
Answer: Graduated cylinder. Its narrow shape and markings provide precise volume readings.
Flashcard 30: What is a hypothesis in an investigation that mixes two or more substances?
Answer: A testable prediction about what will happen. Based on prior knowledge, it guides the investigation.