Unit 1 Scientific Method PT

Some students want to perform an investigation to determine which type of soil holds the most water. The students want to test three different types of soil that have different mixtures of sand, clay, and humus. The students hypothesize that the soil with the greatest percentage of humus will hold the most water. The students plan to test the hypothesis by adding 1 L of water to a soil sample, then measuring the volume of the water that drains from the sample. Which soil type do the students hypothesize will hold the most water?

• Soil with the greatest percentage of sand

• Soil with the greatest percentage of clay

• Soil with the greatest percentage of humus

• Soil with an equal mixture of sand, clay, and humus

Some students want to perform an investigation to determine which type of soil holds the most water. The students want to test three different types of soil that have different mixtures of sand, clay, and humus. The students hypothesize that the soil with the greatest percentage of humus will hold the most water. The students plan to test the hypothesis by adding 1 L of water to a soil sample, then measuring the volume of the water that drains from the sample.

Identify the independent variable in this experiment.

Tags

NGSS.MS-ESS2-4

Some students want to perform an investigation to determine which type of soil holds the most water. The students want to test three different types of soil that have different mixtures of sand, clay, and humus. The students hypothesize that the soil with the greatest percentage of humus will hold the most water. The students plan to test the hypothesis by adding 1 L of water to a soil sample, then measuring the volume of the water that drains from the sample.

Identify the dependent variable in this experiment.

Tags

NGSS.MS-ESS2-4

Some students want to perform an investigation to determine which type of soil holds the most water. The students want to test three different types of soil that have different mixtures of sand, clay, and humus. The students hypothesize that the soil with the greatest percentage of humus will hold the most water. The students plan to test the hypothesis by adding 1 L of water to a soil sample, then measuring the volume of the water that drains from the sample.

Describe two control variables that should be considered to get accurate data in this experiment.

Tags

NGSS.MS-ESS2-4

Some students want to perform an investigation to determine which type of soil holds the most water. The students want to test three different types of soil that have different mixtures of sand, clay, and humus. The students hypothesize that the soil with the greatest percentage of humus will hold the most water. The students plan to test the hypothesis by adding 1 L of water to a soil sample, then measuring the volume of the water that drains from the sample.

How should students analyze their data in order to draw a conclusion?

• Organize the data in a table to get a better look at all of the data.

• Put the data in a bar graph to visualize the data by category.

• Be sure there is only one independent variable and dependent variable, and that all control variables are accounted for.

• All of the choices are valid.

Adding earthworms to a compost pile typically increases the rate at which the organic matter in the pile decomposes. A student wonders whether adding other organisms to the compost pile will have a similar effect on the rate of decomposition. She decides to answer this question by performing an experiment. Which of the following hypotheses could the student test in her experiment?

• Adding bacteria to the compost pile will increase the rate of decomposition.

• Adding plastic to the compost pile will increase the rate of decomposition.

• Adding water to the compost pile will decrease the rate of decomposition.

• Adding earthworms to the compost pile will decrease the rate of decomposition.

Tags

NGSS.MS-LS2-3

NGSS.MS-LS2-4

A farmer hypothesizes that more vegetables will grow in thicker soil. To test this hypothesis, the farmer builds four bins with the following dimensions: The farmer then fills each bin with the same type of soil and plants the same type of vegetable in each bin. At the end of the growing season, the farmer harvests the crops from each bin: - In bin A, the farmer harvested 7 kg of vegetables. - In bin B, the farmer harvested 12 kg of vegetables. - In bin C, the farmer harvested 16 kg of vegetables. - In bin D, the farmer harvested 19 kg of vegetables. Which bin produced the most vegetables?

• Bin A

• Bin B

• Bin C

• Bin D

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-1

Based on these data, complete the following tasks: Create a bar graph representing the relationship between soil thickness and crop yield (i.e., total weight of crops harvested) in each bin. Be sure to label each axis and include a reasonable scale.

Bin A: 7kg of vegetables

Bin B: 12 kg of vegetables

Bin C: 16 kg of vegetables

Bin D: 19 kg of vegetables

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

Do the data support the farmer’s hypothesis? Explain.

• Yes, the data support the farmer's hypothesis.

• No, the data do not support the farmer's hypothesis.

• Explanation: The farmer harvested the most from bin D, 19 kg, which also had the thickest soil. Bins A-C harvested fewer than bin D, and also had shallower soil depths.

• Explanation: The amount of vegetables produced had nothing to do with the farmer's hypothesis

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-1

NGSS.MS-LS2-4

Is the following a scientifically testable question:

Through which type of material do seismic waves (earthquake waves) move the fastest?

• No, this is not a testable question. Seismic waves are invisible, so there is no way for them to be observed.

• Yes, this is a testable question. Scientists have tools where seismic waves occur, and they can collect data for this natural phenomena.

• Yes, this is a testable question. Seismic waves are easy to see moving through different types of materials.

• Yes, this is a testable question. Seismic waves cause lots of damage all over the earth.

Tags

NGSS.MS-PS4-2