OAA Science 4 — Questions and Answers
Question 1: Which gas do plants absorb from the atmosphere during photosynthesis?
- Oxygen
- Nitrogen
- Carbon dioxide (Correct answer)
- Hydrogen
Correct answer: Carbon dioxide
Plants use carbon dioxide (CO₂), water, and sunlight to produce glucose and oxygen during photosynthesis.
Question 2: A ball rolled across a flat surface eventually stops. What force is responsible?
- Gravity
- Friction (Correct answer)
- Magnetism
- Air pressure
Correct answer: Friction
Friction between the ball and the surface converts kinetic energy into heat, slowing and stopping the ball.
Question 3: Which process describes water changing from a liquid to a gas?
- Condensation
- Precipitation
- Evaporation (Correct answer)
- Transpiration
Correct answer: Evaporation
Evaporation is the process by which liquid water absorbs heat energy and changes into water vapor.
Question 4: What is the role of decomposers in an ecosystem?
- They produce food using sunlight
- They hunt and eat other animals
- They break down dead organisms and recycle nutrients (Correct answer)
- They convert nitrogen gas into usable nitrogen
Correct answer: They break down dead organisms and recycle nutrients
Decomposers such as fungi and bacteria break down dead organic matter, returning nutrients to the soil.
Question 5: According to Newton's Third Law of Motion, when you push against a wall, the wall pushes back with:
- A smaller force in the same direction
- An equal force in the opposite direction (Correct answer)
- A larger force in the opposite direction
- No force at all
Correct answer: An equal force in the opposite direction
Newton's Third Law states that every action has an equal and opposite reaction.
Question 6: Which of the following is an example of a chemical change?
- Cutting a piece of paper
- Dissolving sugar in water
- Melting ice
- Burning a candle (Correct answer)
Correct answer: Burning a candle
Burning a candle is a chemical change because new substances (carbon dioxide and water) are produced.
Question 7: Which layer of the atmosphere contains the ozone layer that protects Earth from ultraviolet radiation?
- Troposphere
- Stratosphere (Correct answer)
- Mesosphere
- Thermosphere
Correct answer: Stratosphere
The ozone layer is located in the stratosphere, roughly 15–35 km above Earth's surface.
OAA Science 4
Which gas do plants absorb from the atmosphere during photosynthesis?