Physical Science Unit 1A REVIEW

A scientist notices that plants grow taller when they are exposed to classical music. What is the next step in the scientific method?

• Conduct an experiment

• Draw a conclusion

• Formulate a hypothesis

• Make more observations

Answer explanation

The next step in the scientific method after noticing the correlation between classical music and plant growth is to conduct an experiment to test the hypothesis and gather empirical data.

In an experiment to test the effect of caffeine on heart rate, which of the following would be a constant variable?

• The amount of caffeine given to participants

• The heart rate of the participants

• The age of the participants

• The time of day the experiment is conducted

Answer explanation

In an experiment to test the effect of caffeine on heart rate, the amount of caffeine given to participants would be a constant variable to ensure consistency in the study.

Why is a control group important in an experiment?

• To ensure that the experiment is ethical

• To provide a baseline for comparison

• To manipulate the independent variable

• To measure the dependent variable

Answer explanation

A control group is important in an experiment to provide a baseline for comparison between the group that receives the treatment and the group that does not.

In an experiment to test the effect of different light colors on the growth of bacteria, what is the independent variable?

• The growth rate of the bacteria

• The type of light color

• The temperature of the environment

• The size of the bacteria culture

Answer explanation

In an experiment to test the effect of different light colors on the growth of bacteria, the independent variable is the type of light color.

When graphing the results of an experiment, which axis typically represents the independent variable?

• X-axis

• Y-axis

• Z-axis

• It depends on the experiment

Answer explanation

When graphing the results of an experiment, the independent variable is typically represented on the X-axis.

Which metric unit would you use to measure the width of a computer screen?

• Millimeter (mm)

• Centimeter (cm)

• Meter (m)

• Kilometer (km)

Answer explanation

To measure the width of a computer screen, you would use the metric unit Millimeter (mm) as it provides a more precise measurement for smaller objects like screens.

A chef wants to measure the mass of a single egg. Which metric unit is most appropriate?

• Gram (g)

• Kilogram (kg)

• Milligram (mg)

• Microgram (µg)

Answer explanation

The most appropriate metric unit to measure the mass of a single egg is the Gram (g) as it is commonly used for small weights like that of an egg.

What metric unit would you use to measure the amount of water in a bathtub?

• Milliliter (mL)

• Liter (L)

• Kiloliter (kL)

• Cubic centimeter (cm³)

Answer explanation

You would use the metric unit 'Liter (L)' to measure the amount of water in a bathtub.

A scientist is measuring the boiling point of a new liquid substance. Which temperature scale is most appropriate?

• Celsius (°C)

• Fahrenheit (°F)

• Kelvin (K)

• Rankine (°R)

Answer explanation

The most appropriate temperature scale for measuring the boiling point of a new liquid substance is Kelvin (K) as it is an absolute temperature scale with zero at absolute zero, making it ideal for scientific measurements.

If a recipe calls for 200 milliliters of milk, how many liters is that?

• 0.2 liters

• 2 liters

• 20 liters

• 200 liters

Answer explanation

To convert milliliters to liters, divide by 1000. Therefore, 200 milliliters is equal to 0.2 liters.