Which rule below would you NOT follow when using a Bunsen burner?

• Keep the gas tap closed when attaching the rubber hose from the Bunsen burner.

• Wear protective clothing and safety glasses.

• Long hair must be tied back.

• Place the Bunsen burner directly onto the bench.

When heating a test tube, it should be:

• Pointed away from yourself and other students.

• Filled completely with the liquid being heated.

• Held with two fingers.

• Heated over a tripod and gauze mat.

The measurements that are made in experiments always contain an amount of inaccuracy called “error”.

A group of students wanted to know whether the ‘period’ (the time for one complete movement forward and back) is the same for all playground swings.

 

They decided to measure the periods of several different playground swings.

 

 

What method must the students use to get the most accurate value for the period of each playground swing?

• Each student measures one period for each playground swing then finds the average of their measurements.

• Each student measures one period for a different playground swing then finds the average of their measurements.

• For each playground swing, measure five periods and divide this by five.

• For each playground swing, measure one period and divide this by five.

After performing an experiment, scientists write a report that gives details about the experiment. The ‘aim’ section of a report is:

• an outline of the results of the experiment.

• a written explanation of the results of an experiment.

• an outline of the observations made during an experiment.

• a statement that describes the reason for doing the experiment.

The graph shows the change in the concentration of carbon dioxide gas (CO₂) in the atmosphere from 1960 to 2006.

The smooth line represents the average yearly CO₂ concentration in the atmosphere, in parts per million (ppm). The oscillating line shows the fluctuations in CO₂ throughout each year.

From the graph, what is the concentration of carbon dioxide in the atmosphere in the year 2015?

• 380 ppm

• 388 ppm

• 398 ppm

• 418 ppm

Different sizes, materials, and drop heights were used in an experiment designed to test parachutes, and the time taken to fall was recorded.

To determine the effect of drop height on the time taken to fall, which of the following should be kept the same?

• Drop height

• Drop height and the size of the parachute

• The size and the material type of the parachute.

• The material type and the drop height.

Choose the best possible answer.

A hypothesis

• is a guess.

• can be tested with an experiment.

• is a statement you must write in your science report.

• would not have a clue what it is.

When performing an experiment there are three sets of variables that need to be considered.

Which statement below is correct about the variables?

• Independent variable is measured in an experiment.

• Controlled variable is measured in an experiment.

• Dependent variable is measured in an experiment.

• Extraneous variables are measured in an experiment.

A Year 8 student is designing an experiment to test what variables affect the quality of scones baked in an oven.

Which of the following is the least logical variable for this experiment?

• The size of the scone.

• The length of time the scones are in the oven.

• The temperature of the oven.

• The day of the week when the experiment is performed.

Explain how "observations" are different from "inferences" in science.