PRAXIS Elementary Education: Science Content Knowledge 2 — Questions and Answers
Question 1: Which process describes water changing directly from a solid to a gas without becoming a liquid?
- Condensation
- Sublimation (Correct answer)
- Evaporation
- Precipitation
Correct answer: Sublimation
Sublimation is the phase change from solid directly to gas, as seen in dry ice.
Question 2: A student observes that a metal spoon in hot soup becomes warm at the handle. Which heat transfer method is responsible?
- Convection
- Radiation
- Conduction (Correct answer)
- Insulation
Correct answer: Conduction
Conduction transfers heat through direct contact between particles in a solid.
Question 3: In a food web, organisms that break down dead matter and return nutrients to the soil are called what?
- Producers
- Herbivores
- Decomposers (Correct answer)
- Predators
Correct answer: Decomposers
Decomposers like fungi and bacteria recycle nutrients from dead organisms.
Question 4: Which of the following is a renewable resource?
- Coal
- Natural gas
- Wind (Correct answer)
- Petroleum
Correct answer: Wind
Wind is renewable because it is naturally replenished and not depleted by use.
Question 5: What force keeps the planets in orbit around the Sun?
- Magnetism
- Gravity (Correct answer)
- Friction
- Electricity
Correct answer: Gravity
Gravity is the attractive force that keeps planets orbiting the Sun.
Question 6: Which part of a plant cell carries out photosynthesis?
- Nucleus
- Mitochondria
- Chloroplast (Correct answer)
- Vacuole
Correct answer: Chloroplast
Chloroplasts contain chlorophyll and capture light energy for photosynthesis.
Question 7: A controlled experiment should have how many variables changed at a time to test a clear cause?
- One (Correct answer)
- Two
- Three
- As many as possible
Correct answer: One
Changing only one variable isolates its effect, keeping the test valid.
PRAXIS Elementary Education: Science Content Knowledge 2
Which process describes water changing directly from a solid to a gas without becoming a liquid?