SCIENCE 9 - 3rd Quarter Reviewer

Which of the following statements CORRECTLY compares the three magma compositions?

• I, II and III

• II and III

• I and II

• I and III

What would magma with the LOWEST viscosity contain?

• a high silica content and high temperature

• a high silica content and low temperature

• a low silica content and high temperature

• a low silica content and low temperature

Answer explanation

Magma with the LOWEST viscosity would contain a low silica content and high temperature, making it less viscous and more fluid.

What can be inferred about the silica content and temperature of magma if it has a HIGH viscosity?

• a high gas content and high temperature

• a high gas content and low temperature

• a low gas content and high temperature

• a low gas content and low temperature

Answer explanation

High viscosity in magma indicates high gas content and low temperature.

Which statement is TRUE?

• I and II

• I and IV

• III and IV

• II and III

Several kilometers from a shield volcano, a geologist observes an old lava flow made up of dark-colored basalt rock. What should geologists infer about magma?

• It has low viscosity.

• It has high viscosity.

• It has medium viscosity.

• It has high silica content.

Answer explanation

Geologists should infer that the magma has low viscosity based on the observation of an old lava flow made up of dark-colored basalt rock.

If a volcano’s magma is low in silica, how would you describe its volcanic activity?

• It will erupt quietly.

• It will remain dormant.

• It will erupt explosively.

• It will produce dark-colored lava.

Answer explanation

A volcano with low silica magma erupts quietly due to its low viscosity, allowing gases to escape easily without causing explosive eruptions.

Which shows the correct sequence of the flow of energy in a Geothermal Powerplant?

• electricity → steam → generator → turbine → hot water

• hot water → generator → turbine → steam → electricity

• generator → turbine → steam → hot water → electricity

• hot water → steam → turbine → generator → electricity

Answer explanation

The correct sequence of the flow of energy in a Geothermal Powerplant is hot water → steam → turbine → generator → electricity.

Which of the following statements is TRUE?

• Geothermal energy came from the Greek words “geo” and “thermos”.

• Geothermal energy supply is limited.

• Geothermal energy is a renewable energy source.

• Geothermal energy converts heat to electricity using conventional and supercritical system.

Answer explanation

Geothermal energy is a renewable energy source, making it the true statement among the options provided.

Which of the following processes in a Geothermal Powerplant happens AFTER hot water is pumped from deep underground through a well with high pressure?

• The steam cools off in a cooling tower and condenses back to water.

• When the water reaches the surface, the pressure drops, which causes the water to turn into steam.

• The cooled water is pumped back into the Earth to begin the process again.

• The steam spins the turbine, which is connected to the generator that produces electricity.

Answer explanation

The correct choice is when the water reaches the surface, the pressure drops, causing the water to turn into steam.

Which of the following BEST describes climate?

• The weather that occurs in the atmosphere within a day.

• The pattern of weather that occurs in a region over a long period of time.

• The pattern of weather that occurs in a region over a short period of time.

• The disturbance in the atmosphere that happens in a long period of time.

Answer explanation

Climate is the pattern of weather that occurs in a region over a long period of time, making it the best description among the options provided.