Stanford Achievement Test Stanford Achievement Science Concepts 4 — Questions and Answers
Question 1: Which of the following is an example of a physical change?
- Iron rusting
- Wood burning
- Paper being cut (Correct answer)
- Milk souring
Correct answer: Paper being cut
Cutting paper changes only its shape and size without creating a new substance, making it a physical change.
Question 2: What do scientists call the path that Earth travels around the Sun?
- Rotation
- Revolution
- Orbit (Correct answer)
- Axis
Correct answer: Orbit
Earth's orbit is its elliptical path around the Sun, taking approximately 365.25 days to complete one trip.
Question 3: Which part of a plant absorbs water and minerals from the soil?
- Leaves
- Stem
- Roots (Correct answer)
- Flowers
Correct answer: Roots
Roots anchor the plant in the soil and absorb water and dissolved minerals needed for growth and photosynthesis.
Question 4: What type of energy is stored in food and released when organisms digest it?
- Kinetic energy
- Chemical energy (Correct answer)
- Thermal energy
- Light energy
Correct answer: Chemical energy
Chemical energy is stored in the molecular bonds of food and released through cellular respiration to power life processes.
Question 5: Which of the following best describes an ecosystem?
- A single species living in an area
- All living and nonliving things interacting in an area (Correct answer)
- Only the plants in a habitat
- The climate of a region
Correct answer: All living and nonliving things interacting in an area
An ecosystem includes all living organisms and the nonliving environment—like soil, water, and air—interacting together.
Question 6: What happens to the size of a pupil (the dark circle in your eye) in bright light?
- It stays the same
- It gets larger
- It gets smaller (Correct answer)
- It disappears
Correct answer: It gets smaller
In bright light, muscles in the iris contract to make the pupil smaller, reducing the amount of light entering the eye.
Question 7: Which of the following materials is the best conductor of electricity?
- Wood
- Rubber
- Copper (Correct answer)
- Glass
Correct answer: Copper
Copper is an excellent conductor because its electrons move freely, allowing electric current to flow easily through it.
Stanford Achievement Test Stanford Achievement Science Concepts 4
Which of the following is an example of a physical change?