Nature of Science 8th Qtr1

The factors in an experiment that can be changed. 

• variables
• quantitative data
• hypothesis
• steps

Rigoberto writes down his hypothesis that more salt will dissolve in cold water than in warm water.  He adds salt to different temperatures of water and records his observations including the amount of undissolved salt.  He finds that there is more salt dissolved in warm water than cold water.  What should Rigoberto do next to make sure that his conclusion is valid?

• do another investigation with sugar
• repeat his investigation using a different liquid than water
• repeat his investigation to see if his results are the same
• change his results to match his original hypothesis

Austin is studying states of matter by heating water in a pan.  Which statement from his notebook is an observation?

• It is hard to estimate the size of the bubbles.
• Tiny bubbles form on the bottom of the pan.
• The bottom of the pan must be very hot.
• I think there is air in the bubbles.

Tags

NGSS.MS-PS1-4

A scientist says that she has made an important discovery about sound waves.  What needs to happen for most other scientists to accept her results?

• The scientist has to explain her results to other scientists.
• Many scientists need to review the results.
• The scientist needs to publish her results in a journals.
• Other scientists need to be able to get the same results.

Alejandro wanted to find out which of his friends was the strongest.  He asked each of his friends to come to his lab three different times and lift some weights.  Alejandro wrote down how much weight each person could lift.  How was his investigation different from an experiment?

• Alejandro did not test a hypothesis
• Alejandro did not make any observations
• Alejandro did not repeat his tests.
• Alejandro did not collect any data.

1.  Why is it important to have a control in an investigation?

• Controls are used to show that different results are caused by changing the variable.
• Without controls, it is not possible to make a hypothesis.
• A control helps us to predict.
• Controls are the answer to the investigative question.

A valid scientific investigation must be able to be 

• graphed.
• predicted.
• replicated (which means repeated)
• observed.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS2-5

A scientist tested an exercise machine.  He had two groups of volunteers.  Group A exercised every day for a month.  Group B did not exercise.  He made the table below to compare their muscle strength over 30 days. What is Group B’s role in the scientist’s investigation?

• Group B's role is the variable.
• Group B's role is the control group.

A series of steps used by scientists to solve a problem or answer a question. 

• scientific method
• recipe
• data collection
• metric system

Tags

NGSS.MS-ESS2-5

Jackie sets up an investigation to find out how many paperclips she can pick up with an electromagnet. She takes a long iron nail, wraps insulated wire around it 40 times, and connects the wire ends to the opposite terminals of a D-cell battery.

Jackie touches the tip of the nail to a pile of 100 paperclips and picks up 15 of them. She tries the investigation again and picks up 15 paperclips. Jackie concludes that her electromagnet can pick up 15 paperclips. What should Jackie do to improve her investigation?

• Jackie should use a regular magnet and not an electromagnet.

• Jackie should use a different type of battery.

• Jackie should do more trials to make sure her results are valid.

• Jackie should begin with more than 100 paperclips.

Tags

NGSS.MS-PS2-5