Lab Safety
During a lab, a student notices a strong chemical odor. What should they do first?
Stop, alert the teacher immediately, do not continue without instructions
A student predicts, “If beans grow in sand, then they will be shorter than in soil.” What step is this?
Hypothesis
A student measures a desk as 1.8 m. How many centimeters is this?
180 cm
In an experiment testing how sunlight affects mold growth, what is the independent variable?
Amount of sunlight
You need to measure 25 mL of water very accurately. Which tool do you use?
Graduated cylinder
You accidentally spill water near electrical equipment. What is the safest response?
Turn off equipment if safe, warn others, notify the teacher.
This term is an objective statement based on the five senses
Observation
28° C to K
301 K
Students measure the height of plants each week. What type of data is this: qualitative or quantitative?
Quantitative
A student wants to mass a powder but pours it directly onto the balance pan. What mistake did they make?
Didn’t use a container or weigh boat; could contaminate the balance
What is the last thing you should always do at the end of a lab day?
Clean up everything
During an experiment, the factor you purposely change to test your hypothesis is called the ____.
Independent Variable
7,875 mg to kilograms
0.007875 kilograms
Which of the following best describes what a line graph compares?
A. Quantitative data vs. quantitative data
B. Qualitative data vs. qualitative data
C. Quantitative data vs. qualitative data
D. Parts of a whole
Quantitative data vs. quantitative data
A student needs to mix a chemical solution by swirling it without spilling. Which piece of equipment should they use, and why?
The student should use an Erlenmeyer flask. Its narrow neck prevents spills while swirling, making it safer and easier to mix chemical solutions compared to a beaker.
What does P.A.S.S. stand for?
Pull Aim Squeeze Sweep
The term that explains WHY a phenomenon in nature occurs
Theory
Which unit of measurement would make the most sense for measuring the distance between two towns? A. Micrometers B. Centimeters C. Meters D. Kilometers
Kilometers
In a gum experiment, students chew different brands to test how long the flavor lasts. Name the IV, DV, and one constant.
IV = brand of gum, DV = time flavor lasts, Constant = chewing time/conditions
student needs to pour hot water from a beaker into another container. What tool should they use to safely hold the beaker, and why?
The student should use beaker tongs to safely hold the beaker. This is because the beaker may be hot, and using tongs prevents burns and allows the student to pour the liquid safely and with control.
Two students argue during lab and one starts rushing to “catch up.” Explain why this is dangerous and what should be done.
Rushing increases mistakes/spills/injuries; stop, calm down, work carefully, or ask teacher for guidance
A student is conducting an experiment on different types of soil to see how they affect plant growth. They collect the following data:
The color of the leaves (light green, dark green, yellow) The height of the plants in centimeters The number of leaves per plant The scent of the soil (earthy, musty, or neutral)
Question: Identify which data are quantitative and which are qualitative
Quantitative data (numerical, measurable):
Height of the plants in centimeters – can be measured and expressed as a number.
Number of leaves per plant – a countable value.
Qualitative data (descriptive, non-numerical):
Color of the leaves (light green, dark green, yellow) – describes appearance rather than a number.
Scent of the soil (earthy, musty, or neutral) – a descriptive observation.
Group A:Trial 1: 11.1 mL Trial 2: 12.4 mL Trial 3: 21.0 mL Trial 4: 16.0 mL
Group B:Trial 1: 16.8 mL Trial 2: 17.3 mL Trial 3: 17.0 mL Trial 4: 17.2 mL
If the actual volume of the object is 15.2 mL, which set of data is more accurate? Why?
Group A’s because it is closer to the accepted value.
A student only tests fertilizer on one plant. Why is this a problem, and how could they improve reliability?
Sample size too small; test multiple plants in each group
A student needs to mix two chemicals safely and then measure the temperature change. Which equipment would they need and why?
Beaker or flask for mixing, thermometer for measuring temperature change