The Practice of Science
Professor Wilkins is a biologist studying the habitats of pandas. Last summer she observed pandas in China. What is the best reason for the professor to make careful notes of her observations, procedures, and conclusions?
A. so that other scientists can check her results
B. so that scientists in China will not criticize her work
C. to make sure the habitats of the pandas do not change
D. to draw conclusions about the habitats of animals in other regions
A. so that other scientists can check her results
Henri’s dad was moving cars out of his family’s driveway. The driveway was located in strong sunlight. Henri observed that the family’s white car was cooler inside than the family’s black car. He wants to do an experiment to see whether color makes a difference in the amount of radiant energy a metal surface absorbs. What should he do next?
A. analyze evidence
B. draw a conclusion
C. plan an experiment
D. communicate results
C. plan an experiment
Alyssa is using flower petals, mint leaves, and rubbing alcohol to make a perfume.
What is the main difference between this activity and an experiment?
A. It is not repeatable.
B. There are no variables.
C. There is no hypothesis.
D. It is done under controlled conditions.
C. There is no hypothesis.
Valerie has an object that attracts iron or steel. What force does this object use to attract iron or steel?
A. friction
B. gravity
C. magnetism
D. weight
C. magnetism
True or False: A variable is something that changes in the experiment.
True
Helen plants 24 radish seeds. After 1 week she will count the number of seeds that have germinated. Helen says that more than one half of the seeds will germinate. Which of the following best describes Helen’s statement?
A. inference
B. prediction
C. conclusion
D. observation
A. inference
Ama wants to make potholders as gifts for her friends. She needs to know the color of each person’s kitchen so she can choose potholder loops to match. What skill will Ama use to find out the kitchen colors?
A. collect data
B. form an opinion
C. draw conclusions
D. make a prediction
A. collect data
Greg read the following facts about sow bugs.
1) Sow bug bodies are made up of 7 segments.
2) Sow bugs are crustaceans.
3) Sow bugs have 14 legs.
4) Sow bugs avoid light.
Greg can investigate all of these statements. Greg can do an experiment to test the accuracy of one of the statements. Which statement can he test?
Statement 4
Adrianna pulls a rope to the left and Edward pulls the rope to the right. The rope stays in the same position. Which of these best explains why the rope does not move?
A. The two forces are not equal.
B. The two forces are equal and opposite.
C. The two forces act in opposite directions.
D. Two forces cannot act on the rope at the same time.
B. The two forces are equal and opposite.
Dr. Jones thinks she has just discovered a new plant species. How should she best communicate her findings with other scientists?
A. Try to find another plant to discover.
B. Post her discovery on the internet as fact.
C. Publish her discovery for other scientists to test.
D. Call her friends and tell them about the discovery.
C. Publish her discovery for other scientists to test.
Four students are collecting data about liquids.
Tracey --- Freezing changes a liquid to a solid.
Brian --- Changing the container does not change the mass.
Kim --- Mass is easier to measure than volume.
Bill --- The shape of a liquid may not stay the same.
Which student recorded an opinion and NOT an observation?
Kim
Alyssa is using flower petals, mint leaves, and rubbing alcohol to make a perfume.
What is the main difference between this activity and an experiment?
A. It is not repeatable.
B. There are no variables.
C. There is no hypothesis.
D. It is done under controlled conditions.
C. There is no hypothesis.
Grace drew this graph to show the results of her experiment.
What was the control in this experiment?
A. sample with 1 tablespoon of salt
B. sample with 3 tablespoons of salt
C. sample with no salt
D. temperature
C. sample with no salt
A rock is balanced on the side of a long, sloping hill. A gentle push causes the rock to start rolling down the hill. What happens if the rock is pushed with more force?
A. It stays in place.
B. It gains more friction.
C. Its speed changes more quickly.
D. It experiences less air resistance.
C. Its speed changes more quickly.
Maria pushes with equal force on two objects. Object 1 has twice as much mass as Object 2. Which of the following statements is true?
A. Both objects will remain still.
B. Object 1 will accelerate faster than object 2.
C. Object 2 will accelerate faster than object 1.
D. Both objects will accelerate at the same rate.
C. Object 2 will accelerate faster than object 1.
Ms. Powell is comparing the heights of plants grown in different kinds of soils. She records her thoughts, ideas, observations, and conclusions. Which of the following is a scientific observation that can be tested by repeating the experiment?
A. Different plants always grow to different heights.
B. The plants grown in the soil with clay were shorter.
C. The plants grown in the sandy soil needed more water to grow.
D. Different soils affect plants less than different amounts of water do.
B. The plants grown in the soil with clay were shorter.
Juana is doing an experiment to see the way the heat given off by a light bulb affects temperature in different parts of a room. She collects temperature data in several locations.
What is the control group for this experiment?
A. temperatures of the light bulb
B. temperatures taken near the light bulb
C. temperatures taken in the room before the light bulb is turned on
D. temperatures taken in the part of the room that is farthest from the light bulb
C. temperatures taken in the room before the light bulb is turned on
Donyell is doing an experiment to determine the best fertilization plan for his corn plants. He will test four groups of four plants using this schedule.
Group A Never
Group B Monthly
Group C Weekly
Group D Daily
What is the best reason to have one plant group that gets no fertilizer?
A. to show that all plants need fertilizer
B. to see whether having no fertilizer will make the plant die
C. to have before-and-after pictures to show the benefits of fertilizing
D. to compare that plant group to the others that are fertilized using different plan
D. to compare that plant group to the others that are fertilized using different plan
Genesis is loading a truck. She tries pushing a box up a ramp, but the box does not move. Which is the best explanation of why the box does not move?
A. Genesis needs to use a force in the opposite direction.
B. There is not enough friction to allow the box to move.
C. The box is not heavy enough to overcome Gensis’ force.
D. A force in the opposite direction balances the pushing force.
D. A force in the opposite direction balances the pushing force.
Both cookies and gelatin desserts are solids although their textures are very different. What do they have in common that makes them solids?
A. They both may be eaten.
B. They both keep their own shape.
C. They both can move around in a container.
D. They both are made of solids such as sugar.
B. They both keep their own shape.
John is measuring how adding salt to water changes the time it takes the water to boil. John concludes that water boils at a higher temperature when salt is added. Which of these observations is evidence to support Hoy’s conclusion?
A. Stirring the water made it boil faster.
B. All of the salt did not dissolve in the water.
C. The water with salt did not boil until the temperature was 104 °C (219 °F).
D. Adding more salt may change the boiling temperature even quicker and to a greater degree.
C. The water with salt did not boil until the temperature was 104 °C (219 °F).
Rory is setting up an experiment to see how plants react to drought conditions. A drought is a period of time that has little to no precipitation. Which condition will NOT be the same for the control plants as for the drought plants?
A. type of soil used in each pot
B. number of plants in each pot
C. amount of sunlight each plant gets
D. amount of water given to each plant
D. amount of water given to each plant
Melissa does an experiment to see which type of insulator keeps a cup of boiling water hot the longest.
What will Melissa use as a control in this experiment?
A. empty cup
B. cup of boiling water with no insulator
C. cup of boiling water with no thermometer
D. cup of water that is heated to keep it boiling
B. cup of boiling water with no insulator
A boy pulls upward on a cardboard box but cannot lift it. Which is the best explanation of why the boy cannot lift the box?
A. Earth's magnetic field is too strong.
B. Gravity is stronger than the force he can lift with.
C. Air resistance is pushing down on the box.
D. There is too much friction on the bottom of the box.
B. Gravity is stronger than the force he can lift with.
Which of the following solids will not dissolve in boiling water?
A. baking soda
B. sand
C. sugar
D. table salt
B. sand