Scientific Method
Science re re re repeats
Control what?
Opinion or Observation?
Can you prove it?
100
What is an educated guess?
Hypothesis
100
Judy did an experiment to see what type of metal conducts electricity best. What is the best way for her to be sure that the results are correct?
Judy should repeat the experiment to make sure her results were correct.
100
Adena boils tomato soup to kill all of the bacteria in it. She pours the hot soup into four groups of four small bowls that are just out of the dishwasher. The table shows what she does with each group of samples.
Group 1: cover right away
Group 2: leave in the air one hour and then cover
Group 3: Touch with finger and then cover
Group 4: touch with tongue and then cover
She is going to observe what grows on each sample. Which is the control sample in this experiment?
Group 1
Group 1 is correct because this group is just the soup with little exposure to outside sources of bacteria.
100
Jade and Keith learned that clouds have different shapes and colors and that they contain different amounts of water. Keith says that seeing clouds means it is going to rain.
Is Keith's statement an opinion, prediction, conclusion, or observation?
Opinion
Keith gives neither reasons nor evidence to support the statement. He based his statement on his own thoughts and ideas only.
100
Two students are doing an experiment to find out the way the temperature of water affects the speed at which powdered drink mix dissolves. They use one pitcher of ice water and one pitcher of water at room temperature. They conclude the drink mix dissolves faster in warmer water. Which of these observations provides evidence to support their conclusion?
A. At the end of the experiment, the ice cubes all melted.
B. At the end of the experiment, the mix dissolves in both pitchers.
C. Stirring the water made the mix dissolve faster in both pitchers.
D. After two minutes, the ice water had some mix that did not dissolve.
Answer D is correct because comparing the amount of mix dissolved is one way to measure the effect of the temperature.
200
A group that receives no experimental treatment is called what?
Control
200
When a scientist performed an experiment, she did not get the results she expected. What should she do?
A. change the results
B. assume her results are correct
C. assume her results are incorrect
D. do the experiment again to test her results
Answer D is correct because repeating the experiment is the best way to test results
200
Anna is doing an experiment about friction. She measures the force needed to pull a toy car up a ramp three times. Then she attaches plastic wrap to the ramp and measures the force needed to pull the car up three times. Next, she puts water on the ramp and measures the force three times. Finally, she puts oil on the ramp and measures the force three times.
The ramp alone.
200
Which of the following is the best example of a scientific observation about magnets?
A. whether a magnet can pick up tacks
B. how temperature changes magnetic attraction
C. how magnetic force is similar to the force of gravity D. which refrigerator magnets a student prefers to use
Answer A is correct because this information can be collected using the senses.
200
Monica is doing an experiment about friction. She measures the force needed to pull a toy car carrying a rock up a ramp. Then she puts a piece of sandpaper on the ramp and measures again. She concludes that sandpaper increases the force of friction. Which of these observations provides evidence to support her conclusion?
A. Using a different scale might change the results. B. More force might be needed if the ramp were higher.
C. More force was needed after the sandpaper was added.
D. Putting a rock in the car increases the mass being pulled.
Answer C is correct because comparing the force needed to pull the car is one way to measure the opposing force of friction.
300
The first step to the scientific method is what?
Ask question/state problem
300
What is the best reason why Basil should record all the steps of his experiment in his report of the results?
A. to test each type of fruit juice the same way
B. to be sure the experiment can be repeated to confirm the results
C. to be sure he uses the same amount of fruit juice for each test
D. to be sure he does not repeat the test using the same fruit juice twice
Answer B is correct because writing down the steps makes it possible to repeat the experiment precisely.
300
Isaak is testing three types of fertilizer to see which is best for growing pumpkins. He plants four groups of pumpkin seeds: one group in garden soil, one group in garden soil with Fertilizer 1, one with Fertilizer 2, and one with Fertilizer 3. Which statement is true?
A. The control consists of the seeds planted in soil alone.
B. The control for this experiment is the pumpkins. C. Isaak will not be able to tell which type of soil is best.
D. The growth of the pumpkins is the control for this experiment.
Answer C is incorrect because Isaak will judge which fertilizer is best by observing plant growth
300
Stewart and his mother want to grow tomato plants. They test different soils to see which would be the best for the tomatoes. They plant tomato plant seedlings in different soils. In a few weeks, they measure the heights of tomato plants grown in the different soils. For this experiment, which of the following is a scientific observation?
A. The plants in the soil with clay were shorter.
B. Repeating the experiment will change the results. C. Pea plants would have worked better than tomato plants.
D. The plants in the sandy soil grow the best-tasting tomatoes.
Answer A is correct because this is measurable data that can be gathered using the senses.
300
Botan compares the time of one back-and-forth swing for each of five pendulums. He uses a 10-degree angle. The masses are the same, but the strings are different lengths. Botan concludes that a longer pendulum swings back and forth more slowly than a short pendulum. Which of these observations provides evidence to support his conclusion?
A. horizontal distance traveled in centimeters
B. times in seconds for each pendulum swing
C. the kind of string used to make the pendulums
D. mass of the balls used to make the pendulums
Answer B is correct because timing the periods of the pendulums provides data to show how string length relates to period.
400
In order for an experiment to be considered valid, what must you be able to do?
Repeat it
400
Rosario did only one trial of her experiment. What is the best reason why she should repeat her experiment?
She should repeat her experiment to check her conclusion.
400
A scientist is doing an experiment. She wants to find the best way to break down sewage waste. She will test a chemical, Bacteria X, and Bacteria Y. What should she use as the control group for this experiment?
A. sewage treated with the chemical
B. sewage treated with Bacteria X
C. sewage treated with Bacteria Y
D. untreated sewage
Answer D is correct because the control group is the sewage with no test substance introduced.
400
Last winter, Armando’s class compared the water content of different snows. They collected samples of cans of snow, then melted each sample and measured the amount of water. For this experiment, which of the following is an opinion?
A. Some snows are drier than others.
B. The water content is related to the temperature. C. The water content is not related to the wind speed.
D. Describing the kinds of snows was difficult.
Answer D is correct because this is a statement that is not supported by reasons or evidence.
400
Tabia drew this picture of what she observed after putting a pencil in a glass of water. Which of these supports the conclusion that the light rays are bent as they pass from the air to the water?
A. Some of the water evaporated during the experiment.
B. Cracks in the glass make the pencil appear to be broken.
C. She takes the pencil out of the glass and it is in one straight piece.
D. Changing the temperature of the water does not change the result.
Answer C is correct because comparing what she sees when the pencil is in the water and out of the water is one way to observe the refraction of light rays.
500
I have a new protein powder. I have 50 people that just drink water, 50 that drink the water with the powder. I ask them to run one mile. What is the control, Independent Variable, Dependent Variable?
Control-only water IV-powder and water DV-time to run mile
500
Marshall does an experiment to see what type of insulator keeps a cup of boiling water hot the longest. What is the best way for Marshall to be sure that his results are accurate?
A. do more trials of the experiment
B. use different materials as insulators
C. record the data in two types of graphs
D. form conclusions based on his observations
Answer A is correct because repeating an experiment will check the accuracy of the results
500
A scientist gathers water from three different areas of a pond. He prepares several Petri dishes of a growing solution. He puts a drop of water from one area of the pond into each group of three Petri dishes. One Petri dish group has just the growing solution in it. He covers the Petri dishes. He leaves the samples on a counter for several days and compares the algae that grow. Why does he have one Petri dish group with just the growing solution in it?
To find out whether any algae grow in just the solution
It is important to differentiate between algae that are introduced by the solution and algae introduced by the experiment.
500
Arthur is comparing different kinds of rocks. What should Arthur use to make the best scientific observations about the samples?
Arthur should use his senses because it is the most direct way to collect or measure scientific information.
500
Jean-Michel is studying constellations. He goes outside on a clear night and writes down his thoughts, ideas, observations, and predictions. Which of these is NOT a recorded observation that can be tested?
A. Some constellations have more stars than others. B. Some stars in a constellation are brighter than others.
C. There may be intelligent life in one of the constellations.
D. The constellations are not in the same place during different seasons.
Answer C is correct because this is an opinion or conjecture and not a recorded observation. There is no way to prove this statement false.