SC.6.N.1.1 - Experimental Design

Scientists conduct experiments to collect evidence. Which of the following is the best definition of the word experiment as used by scientists?

• Making a series of observations

• the formation of a hypothesis

• a structured test of a hypothesis

• a chance to try something new

Tags

NGSS.MS-PS2-2

Sarah wants to know where in her garden chamomile would grow the best. She thinks chamomile will grow best in the corner of the garden that gets the most sunlight. To test her hypothesis, she decides to plant several groups of chamomile in her garden as an experiment.

Which of the following variables should Sarah keep the same between all the chamomile plants?

• the location of the plants

• the type of plants

• the height of the plants

• all of these

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-1

NGSS.MS-LS2-4

Jack is planning an experiment to see how temperature can affect the reproduction rate of a certain species of bacteria.

Jack is listing some of the variables that could affect the outcome of the experiment. Which of the following variables should be included on his list?

• time of year, clothes Jack wears, Petri dish mass

• temperature, light level, species of bacteria

• time of day, color of walls in lab, Jack's height

• food Jack eats, day of the week, number of pages in log book

Tags

NGSS.MS-LS2-4

Ben wants to know how a toy car's initial speed affects the distance that it is able to travel before it is stopped by friction, so he sets up the following experiment.

In Ben's experiment, he places a toy car on a smooth, flat surface. Then, Ben applies varying amounts of force to the back of the car and measures the car's initial speed using a radar gun. The toy car is allowed to decelerate on its own until it stops. Finally, Ben measures the total distance that the car traveled.

What is the outcome variable (dependent variable) in Ben's experiment?

• the initial speed of the toy car

• the type of car that was used

• the total distance that the car traveled

• the friction between the car and the surface

Tags

NGSS.MS-PS2-2

NGSS.MS-PS3-5

Maria wants to determine which type of disinfectant kills the most bacteria.

Which of the following is the best way for Maria to determine this?

• Put the same amount and species of bacteria on ten identical plates, and add a different disinfectant to each plate.

• Ask ten different companies that make disinfectants which type is best.

• Interview ten different people to determine which type of disinfectant they prefer

• Put the same amount and species of bacteria on ten identical plates, and add ten different kinds of disinfectant to each plate

Tags

NGSS.MS-ETS1-3

NGSS.MS-PS1-2

Juan wants to see how air expands when it is heated. He is able to use any of the following supplies - a balloon, a heat lamp, a spring scale, and a meter stick.

Which is the best procedure to follow for the experiment?

• Inflate the balloon, heat the balloon using the heat lamp, and measure the weight of the balloon with the spring scale.

• Use the spring scale to measure the weight of the balloon before and after it is blown up

• Inflate the balloon, measure the width of the balloon, heat the balloon using the heat lamp, and then measure the width again.

• Measure the weight of the deflated balloon, inflate the balloon, heat the balloon with the heat lamp, then measure the inflated balloon's width.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

Which of the following statements describes all the variables in an experiment?

• All variables are measured to provide data for the experimental results

• All variables affect the results of the experiment

• All variables are changed from one part of the experiment to another

• All variables are kept the same from one part of the experiment to another

Beth wanted to find out whether or not salt affects how quickly ice melts. She used an ice cube tray to make 10 ice cubes of the same shape and size. Then, she placed the ice cubes on the same windowsill. She sprinkled each ice cube with one teaspoon of salt, and timed how long it took for the cubes to melt. She recorded all of the data.

If someone else read the data, would he or she be able to make an accurate conclusion about the effect of salt on ice?

• No, because Beth should have used a different amount of salt on each of the ice cubes.

• No, because the data does not show how quickly the ice would have melted without the salt.

• Yes, because using 10 ice cubes gives enough trials for the results to be accurate

• Yes, because Beth used only one independent variable and everything else was the same

Anna is conducting an experiment to determine how weather affects cell phone reception. She is trying to decide the best way to conduct her experiment in order to collect meaningful data.

Which of the following experiments would help Anna collect the best data?

• Test a cell phone's reception in one location with clear weather and in another location with rainy weather

• Test a cell phone's reception in the exact same location under various atmospheric conditions

• Test different cell phones in different locations on days with clear weather.

• Test different cell phones in different locations on days with rainy weather.

Tags

NGSS.MS-ESS2-5

NGSS.MS-ETS1-2

In school, Jarrett learned that salt lowers the freezing point of water. He wants to test this in a home experiment. He combines 1.0 grams of salt and 500 milliliters of water in a container. In an identical container, he pours 500 milliliters of water and does not add salt to it.

What should Jarrett do next?

• Place both containers in a freezer, and record the temperatures at which they begin to freeze

• Mix the two samples of water together in a 1.0-liter container, and bring them to a boil on a stove

• Place the pure water in a freezer and the salt water in a refrigerator

• Place the salt water in a freezer and the pure water in a refrigerator

Tags

NGSS.MS-PS1-2