PSSA Science - Skills practice

A scientist is observing a rare monkey in the jungle, and the monkey begins exhibiting an odd behavior. The scientist thinks this behavior may not have been observed in this species before, but he is not certain. The scientist records video of the behavior and takes many detailed notes.
The scientist becomes very excited about his finding and plans to share it with other scientists. The best way for him to communicate and defend his finding would be to 

• immediately write a report claiming a newly discovered behavior, and then check later to see if others have observed it before.
• defend his finding as a new discovery, even if another scientist has already published a report about the behavior.
• confirm that the behavior has not been observed before, and then present his finding in a report.
• wait until other scientists ask him about his trip to the jungle, and then tell them about his finding.

Dr. Peterson does an experiment to research the growth rate of mice. He has two groups of mice. He feeds one group a type of food and adds chemical A, which is supposed to increase growth rate. The other group he feeds the same food without chemical A added. His research shows that chemical A increases growth rate by 30%. He does the experiment 4 times and comes up with the same result each time.
Dr. Peterson concludes that chemical A does increase the growth rate of mice. Is Dr. Peterson's conclusion supported by scientific knowledge? 

• No; scientific knowledge never comes from research or experiments.
• No; science cannot be used to research small animals such as mice.
• Yes; his conclusion is supported by evidence from his experiment.
• Yes; any study that involves a percentage is based on scientific knowledge.

Inferences are 

• never made by scientists.
• exactly the same as observations.
• questions that are made by studying conclusions or predictions.
• conclusions or predictions that are made by studying observations.

The production of oxygen from a reactant in a chemical reaction is shown. The graph shows the volume of oxygen produced as a function of the amount of reactant consumed. If the trend continues, how much oxygen will be produced when 25 g of the reactant is consumed? 

• 3.0 ml
• 1.5 ml
• 5.0 ml
• 4.0 ml

Quantitative observations always include _______. 

• words
• symbols
• numbers
• time

What is the volume of the liquid in the graduated cylinder shown above? 

• 25.6 L
• 23.1 L
• 25.6 mL
• 23.1 mL

When scientists use one of their five senses to gather information, they are 

• making an observation.
• predicting a relationship
• drawing a conclusion.
• making an inference.

The triple-beam balance shown above measures in grams. What is the mass of the chick? 

• 10 kg, 7.5 g
• 175 g
• 17.5 g
• 10.75 g

Tony recorded data from his chemistry experiment in the following table. Which of the categories from Tony's data table includes qualitative observations? 

• temperature
• volume
• mass
• color

A student would like to determine how heating a liquid changes its volume. The student hypothesizes that the liquid will increase in volume. The following list shows the steps taken by the student in order to test the hypothesis.
 1. Select the liquid to test.
2. Place the liquid in a sealed container. 3. Use a Bunsen burner to heat the liquid by 10°C.
4. Measure the volume of the liquid.
5. Record the results.
What is wrong with how the student conducted the investigation? 

• The student should have increased the temperature of the liquid by more than 10ºC.
• The length of time it took for the liquid to be heated should be measured.
• The hypothesis was not valid because it is impossible for liquids to change in volume.
• The volume of the liquid should be measured before it is heated.