ISASP Science 3 — Questions and Answers
Question 1: Earth's tectonic plates move because of convection currents in the:
- Crust
- Mantle (Correct answer)
- Outer core
- Inner core
Correct answer: Mantle
Heat-driven convection currents in the semi-fluid mantle cause tectonic plates to move.
Question 2: A student mixes vinegar and baking soda and observes bubbling and fizzing. This is evidence of a:
- Physical change because no new substance forms
- Chemical change because a new gas is produced (Correct answer)
- Physical change because the substances can be separated
- Nuclear change because energy is released
Correct answer: Chemical change because a new gas is produced
The production of carbon dioxide gas (CO₂) is a new substance, indicating a chemical change has occurred.
Question 3: Which organelle is responsible for producing energy (ATP) in animal cells through cellular respiration?
- Nucleus
- Ribosome
- Mitochondria (Correct answer)
- Cell membrane
Correct answer: Mitochondria
Mitochondria carry out cellular respiration, converting glucose and oxygen into ATP energy the cell can use.
Question 4: The Law of Conservation of Mass states that in a chemical reaction:
- Mass is created from energy
- The total mass of products equals the total mass of reactants (Correct answer)
- Mass is destroyed when bonds break
- Products always weigh more than reactants
Correct answer: The total mass of products equals the total mass of reactants
Matter is neither created nor destroyed in a chemical reaction, so the total mass of reactants equals the total mass of products.
Question 5: A student swings a pendulum and measures how long each swing takes. Which factor will most affect the period (time per swing) of the pendulum?
- The mass of the pendulum bob
- The color of the string
- The length of the string (Correct answer)
- The initial push strength
Correct answer: The length of the string
The length of the pendulum string is the primary factor determining its period; longer strings produce slower swings.
Question 6: Which best describes the role of decomposers in an ecosystem?
- They convert sunlight into chemical energy
- They hunt and consume primary consumers
- They break down dead organisms and return nutrients to the soil (Correct answer)
- They compete with producers for space
Correct answer: They break down dead organisms and return nutrients to the soil
Decomposers like bacteria and fungi recycle nutrients from dead organisms back into the soil, making them available for producers.
Question 7: Which of the following is a renewable energy source?
- Coal
- Natural gas
- Petroleum
- Wind (Correct answer)
Correct answer: Wind
Wind is a renewable energy source because it is naturally replenished and will not run out, unlike fossil fuels.
ISASP Science 3
Earth's tectonic plates move because of convection currents in the: