Vocabulary
The first thing you look for when formatting your CER
Evidence
how many independent variables can be measured in a controlled experiment?
one
An experiment is performed on plants to see how different liquids affect plant growth. Each plant in the experiment is given a different liquid; water, apple juice, or milk. Each plant has the same amount of soil, same amount of sunlight, and the same amount of liquid. In this investigation, what is the independent variable?
type of liquid
Mr. S set up an experiment to see how the mass of a ball affects the distance it rolls off a ramp. Identify the dependent variable.
distance traveled by the ball
Some teachers think that students learn best in rooms with music. They teach the same
lesson, but one class plays music in the background and the other is not. They give a test and compare the results. which is the group group?
No music playing
Use scientific principles and knowledge that you have about the topic to explain why your evidence (data) supports your claim.
Reasoning
When experimenting with the growth of a plant, a scientist uses three (of the same type of) plants, two different fertilizers, equal light, and equal water. What type of variable is the fertilizer?
Independent
What effect does decreasing the temperature of a room have on a lifespan of a battery? Which variable is italicized?
What is independent variable
Ben makes five paper helicopters with different wing lengths. He drops them the same way from a height of two meters for five trials each. He records the amount of time it takes for each helicopter to fall to the ground.
What is the dependent variable?
Amount of time it takes the helicopter to hit the floor
Mrs. Cole wants to know if she gives teachers a free jeans day, it will make them smile more. She gives
half the teachers a free jeans day and the other half get nothing. She then records the number of times
the teachers smiled that day. Which is the control group?
Half with nothing, no free jeans day
A one sentence statement about your investigation
Claim
Sabrina wants to test which brand of popcorn pops the most kernels. She picked a Giant Eagle brand, Orville Redenbacher, and PopSecret. All three bags started with the same number of kernels. She popped each for 3 minutes in the same microwave, and then counted the number of kernels left over. What is her independent variable?
brand of popcorn
Angelina performed an investigation to find out how the concentration of salt water affected the hatching of brine shrimp. What is the INDEPENDENT Variable?
Salt water concentration
An experiment is performed on plants to see how different liquids affect plant growth. Each plant in the experiment is given a different liquid; water, apple juice, or milk. Each plant has the same amount of soil, same amount of sunlight, and the same amount of liquid. In this investigation, the dependent variable is
growth of the plant
. A student wanted to test how the mass of a paper airplane affected the distance it would fly. Paper clips were added before each test flight. As each paper clip was added, the plane was tested to determine how far it would fly.
What is the control?
Plain paper airplane
variable that displays the "Data" results
dependent variable
Mrs. Smith's classes were testing to see which soil would support plant growth. They used the same seeds, same pots, gave the same amount of water to each, and put them all in the same location. What is the independent variable?
type of soil
David performed an investigation to find out how temperature affects crystal growth. What is the INDEPENDENT Variable?
Temperature
Jessie is concerned about how tired his classmates seem. He created a drink that he thinks will boost their energy. He recruits 100 classmates with a history of tiredness. He has 50 of them drink his new special energy drink. The other 50 drink a beverage that looks like the special energy drink, but is just water and food coloring. Both groups were told that they were getting the special drink that would boost energy. After 2 hours, 30 classmates in the first group reported having more energy and 8 classmates in the second group reported having more energy.
What is the dependent variable?
amount of energy
.
Zack is testing whether temperature affects the distance a rubber band can be stretched before it breaks. He heats three rubber bands in a microwave oven. He puts
three in a jar on the kitchen counter. He puts three in the refrigerator and three in the freezer.
Which is the control group?
Rubber bands in the jar
What axis is the dependent variable graphed on?
y-axis
.
A scientist thinks that noodles will cook faster faster when salt is added to the water. He tests two groups of
noodles, one with salt in the water and one in water with no salt. He records how fast they boil. Which is the control group?
One with no salt added
Kira wants to test which type of soda creates the biggest foam explosion when adding a Mentos candy. She chose Sprite, Coke, and Mountain Dew. One at a time, she added a single Mentos candy and measured the height of the foam eruption. Mountain Dew created a foam eruption of 7 inches. Coke and Sprite tied at 5 inches. What is her independent variable?
type of soda
How does watching TV during studying affect a student’s test grades? Which variable is italicized?
dependent variable
Pat performed an investigation to find out under which color of light plants grow best. What variable should be CONTROLLED?
the color of light received
the amount of light the plant received
the number of different colors of light tested
nothing needs to be controlled
the amount of light the plant received