All flashcards
Flashcard 1: Which option best describes taring a balance before weighing a substance in a container?
Answer: Set the container on the balance and press tare to zero it. Removes container weight from the measurement.
Flashcard 2: What should you do to a balance before measuring to make sure it reads correctly?
Answer: Zero (tare) the balance. Ensures accurate readings by starting from zero.
Flashcard 3: What unit is most commonly used to record the weight of small substances in 5th grade science?
Answer: Grams (g). Standard metric unit for measuring small masses in lab work.
Flashcard 4: What tool is used in science class to measure the weight of a substance in grams?
Answer: A balance (such as a triple-beam balance or digital balance). Balances measure mass precisely in science experiments.
Flashcard 5: Which option best describes how to record data for before-and-after weight measurements in an investigation?
Answer: Use a data table with initial weight, final weight, and change in weight. Organized data helps track changes systematically.
Flashcard 6: Which option is the most accurate practice when weighing before and after heating or cooling?
Answer: Use the same container for both measurements. Eliminates container weight as a variable.
Flashcard 7: Identify the best way to compare weights before and after heating, cooling, or mixing.
Answer: Measure initial weight and final weight using the same balance and units. Ensures consistent and comparable measurements.
Flashcard 8: What is the correct term for the weight recorded before heating, cooling, or mixing a substance?
Answer: Initial weight. The starting measurement before any changes occur.
Flashcard 9: What is the correct term for the weight recorded after heating, cooling, or mixing a substance?
Answer: Final weight. The measurement taken after the experiment is complete.
Flashcard 10: Find and correct the measurement mistake: A student records container + substance before, but only substance after.
Answer: Weigh the same items both times (container + substance). Must compare same components for valid results.
Flashcard 11: Choose the correct conclusion: Initial =30g, final =30g after mixing in a sealed container.
Answer: No change in weight (0g change). Sealed containers preserve all matter during mixing.
Flashcard 12: Find the change in weight if the initial weight is 18g and the final weight is 21g.
Answer: +3g. Apply formula: 21g−18g=+3g.
Flashcard 13: Find the change in weight if the initial weight is 25g and the final weight is 22g.
Answer: −3g. Apply formula: 22g−25g=−3g.
Flashcard 14: What is the most likely reason the weight increases after mixing a solid into a liquid in one container?
Answer: Added matter increases the total weight. Combining substances adds their masses together.
Flashcard 15: Which option best explains why weight may seem to decrease after heating an open container?
Answer: Some material can evaporate and leave the container. Water or other liquids turn to gas and escape.
Flashcard 16: What should you do before weighing a hot container to avoid damaging the balance and changing readings?
Answer: Let it cool to a safe temperature before weighing. Heat can damage balance and affect accuracy.
Flashcard 17: Which option best prevents a false weight change when measuring before and after heating?
Answer: Keep the substance from spilling or being lost. Lost material would cause inaccurate weight change.
Flashcard 18: Identify the initial weight if the final weight is 52g and the change in weight is +7g.
Answer: 45g. Subtract change from final: 52g−7g=45g.
Flashcard 19: Identify the final weight if the initial weight is 40g and the change in weight is −5g.
Answer: 35g. Add change to initial: 40g+(−5g)=35g.
Flashcard 20: State the formula for change in weight using initial weight and final weight.
Answer: Change in weight = final weight − initial weight. Subtract starting weight from ending weight.
Flashcard 21: What is the best reason to let a hot container cool before weighing it on a balance?
Answer: Hot air movement can affect the reading and reduce accuracy. Convection currents from heat create unstable readings.
Flashcard 22: What is the most likely reason mass increases after mixing in an open container?
Answer: Matter was added from outside (for example, moisture or extra material). Open containers can absorb moisture or collect particles from air.
Flashcard 23: Which option best prevents mass errors when comparing before and after heating: open cup or covered container?
Answer: Covered container. Prevents gases or vapors from escaping during heating.
Flashcard 24: Which measurement should you record to compare mass before and after cooling: temperature or mass in grams?
Answer: Mass in grams. Mass measurements show if matter was gained or lost during cooling.
Flashcard 25: Identify the correct procedure to compare mass before and after mixing: weigh once or weigh before and after?
Answer: Weigh before mixing and weigh after mixing. Comparing requires measurements at both time points.
Flashcard 26: What should you do if spilled material occurs between the before and after measurements?
Answer: Record that mass was lost; the comparison is not valid for conservation. Spills violate controlled conditions needed for valid comparisons.
Flashcard 27: Identify the total mass after mixing if mA=12g and mB=9g with no loss.
Answer: 21g. Total mass equals sum of parts: 12+9=21.
Flashcard 28: Identify the missing after-mass if change in mass is 0g and mbefore=40g.
Answer: mafter=40g. Zero change means final mass equals initial mass.
Flashcard 29: What is the correct way to ensure a fair comparison of mass before and after heating or cooling?
Answer: Use the same container and the same balance each time. Consistency eliminates variables that could affect measurements.
Flashcard 30: What is the most likely reason mass decreases after heating an open container?
Answer: Some matter escaped, such as water vapor or gas. Open containers allow gases or vapors to escape during heating.