Nature of science - FL Grade 8 SSA Prep

Genesis was setting up an experiment for her science fair project and wanted to test the effect of different liquids on plant growth. She placed different types of plants into individual test tubes and used sugar water, salt water, tap water, bottled water, and pond water. She took measurements every day for three weeks and recorded her measurements in a notebook. What could Genesis do differently to ensure she has a valid experiment?

• limit the experiment to one week

• take measurements more than once a day

• only change one variable at a time in the experiment

• place some test tubes outside to receive more sunlight

Tags

NGSS.MS-ETS1-1

NGSS.MS-LS1-5

A scientist wants other scientists to be able to perform the same experiment she performs in her laboratory. Which is the best way for the scientist to ensure her experiment is replicable by others?

• write detailed notes of each part of the experiment as it is performed

• watch the other scientists complete the experiment over a video call

• take photos of the experiment’s materials and setup

• repeat her experiment before publishing the results

Students in Mrs. Hardin’s class place items in an electrical circuit to determine if they are conductors or insulators. The students work in groups and record whether each item is a conductor or an insulator. What type of scientific investigation are the students performing?

• doing background research on conductors and insulators

• conducting a controlled experiment on conductors and insulators

• comparing the value of different conductors and insulators

• making observations of conductors and insulators

Tags

NGSS.3-5-ETS1-3

Kayden and Abigail test how the steepness of a ramp affects the time it takes a marble to reach the finish line marked “X” on the floor. They obtain identical marbles, books, and ramps from their teacher to perform the experiment. They prop the ramp on 1, 2, and 3 books to alter the steepness of the ramp. Both Kayden and Abigail find that the marble reaches the finish line faster when on the steepest ramp, however, Abigail’s marble reaches the finish line 0.8 seconds faster than Kayden’s. What might account for this difference?

• the steepness of the ramp they used

• the number of trials they performed

• the type of marble they used

• the type of floor surface they used

Tags

NGSS.MS-PS2-2

Anton von Leeuwenhoek first observed single-celled organisms with a simple microscope in the 17th century. Cell theory was not fully formulated until several hundred years later with the development of more complex microscopes. Which of the following best explains how the invention of complex microscopes impacted cell theory?

• The invention of more complex microscopes provided new information and evidence to support the cell theory.

• The invention of more complex microscopes did not improve scientific understanding of the cell theory because it was already proven.

• The invention of more complex microscopes allowed the cell theory to become a law.

• The invention of more complex microscopes did not improve scientific understanding of the cell theory because scientific knowledge does not change.

Maya observes the birds at a local park one afternoon and states that they prefer to search for food in trees rather than on the ground. Why is Maya's statement not considered to be a theory?

• She did not observe the birds at different times or on enough days.

• She did not explain why the birds prefer to search for food in trees rather than on the ground.

• Her statement must be replicated by other scientists and agreed on in the scientific community.

• She did not keep detailed field notes on the types of birds and feeding patterns she observed.

Sherice wants to conserve energy. She wants to find out the lowest water temperature and the shortest amount of time that is needed to wash her clothes and get them clean. She washes one shirt in hot water, one shirt in warm water, and one shirt in cold water. The shirts are identical and have identical stains. She uses the same detergent and washes the shirts for the same amount of time. Why is it important for Sherice to wash the shirts for the same length of time?

• By washing the shirts for the same amount of time, Sherice can find out both the lowest temperature and the shortest length of time that is needed.

• If Sherice does not wash the shirts for the same amount of time, she cannot find the lowest water temperature that is needed.

• It is not important for Sherice to wash each shirt for the same amount of time because she is not testing the length of time that is needed.

• By washing the shirts for the same amount of time, Sherice can find out the shortest length of time that is needed.

Tags

NGSS.MS-PS3-4

Students in Mr. Goff’s class study how the pH of soil affects plant growth. Consider the students’ actions in Experiment 1 and 2 in the table. Which statement best compares Experiment 1 and Experiment 2?

• Experiment 1 represents scientific repetition. Experiment 2 represents scientific replication.

• Experiments 1 and 2 represent scientific repetition.

• Experiment 1 represents scientific replication. Experiment 2 represents scientific repetition.

• Experiments 1 and 2 represent scientific replication.

Tags

NGSS.MS-LS1-5

Not all scientific knowledge is derived from experimentation. Which student did not conduct a scientific experiment according to their conclusion?

• Robbie finds that too little or an excess of water stunts a plant’s growth.

• Kristen learns that when she places more weight on a spring, it stretches farther.

• Samantha concludes that increasing the temperature increases the rate of a chemical reaction.

• Julio observes that the coloring of male birds is brighter than that of female birds.

A materials engineer wants to test how the thickness of insulation in sleeping bags affects their performance in freezing temperatures. She constructs sleeping bags with varying insulation thickness and records the temperature inside the sleeping bag every five minutes for 8 hours at 0°C. Which of the following is the dependent (outcome) variable in her experiment?

• temperature inside the sleeping bag

• sleeping bag with no insulation

• type of insulation material

• thickness of insulation material

Tags

NGSS.MS-PS3-3

NGSS.MS-PS3-4