PRAXIS Elementary Education: Science Content Knowledge 3 — Questions and Answers
Question 1: Which layer of Earth is composed mostly of liquid iron and nickel?
- Crust
- Mantle
- Outer core (Correct answer)
- Inner core
Correct answer: Outer core
The outer core is liquid iron and nickel and generates Earth's magnetic field.
Question 2: The Moon appears to change shape over a month because of what?
- Earth's shadow blocks it
- Its distance from Earth changes
- The angle of sunlight we see reflected (Correct answer)
- Clouds cover parts of it
Correct answer: The angle of sunlight we see reflected
Moon phases result from the changing portion of the sunlit Moon visible from Earth.
Question 3: Which simple machine is a doorknob an example of?
- Lever
- Wheel and axle (Correct answer)
- Pulley
- Inclined plane
Correct answer: Wheel and axle
A doorknob is a wheel and axle that turns to move a latch.
Question 4: What is the primary gas that plants take in for photosynthesis?
- Oxygen
- Nitrogen
- Carbon dioxide (Correct answer)
- Hydrogen
Correct answer: Carbon dioxide
Plants absorb carbon dioxide and release oxygen during photosynthesis.
Question 5: An animal with a backbone is classified as which of the following?
- Invertebrate
- Vertebrate (Correct answer)
- Mollusk
- Arthropod
Correct answer: Vertebrate
Vertebrates are animals that possess an internal backbone or spine.
Question 6: Which instrument would best measure the temperature of a liquid?
- Barometer
- Thermometer (Correct answer)
- Anemometer
- Graduated cylinder
Correct answer: Thermometer
A thermometer measures temperature, while the other tools measure pressure, wind, or volume.
Question 7: When mixing sand and water, what type of change occurs?
- Chemical change
- Physical change (Correct answer)
- Nuclear change
- Combustion
Correct answer: Physical change
Mixing sand and water is a physical change because no new substance forms and it can be separated.
PRAXIS Elementary Education: Science Content Knowledge 3
Which layer of Earth is composed mostly of liquid iron and nickel?