MAP Science 5 — Questions and Answers
Question 1: A student tests whether fertilizer amount affects plant height. What is the independent variable?
- Plant height
- Amount of fertilizer (Correct answer)
- Type of plant
- Amount of sunlight
Correct answer: Amount of fertilizer
The independent variable is the factor the experimenter deliberately changes, here the fertilizer amount.
Question 2: Why should an experiment include multiple trials?
- To make the experiment take longer
- To change the hypothesis each time
- To increase reliability and reduce the effect of random errors (Correct answer)
- To guarantee the hypothesis is correct
Correct answer: To increase reliability and reduce the effect of random errors
Repeating trials helps show results are consistent and not due to chance.
Question 3: When baking soda and vinegar are mixed, bubbles form and the mixture gets colder. What does this show?
- Only a physical change occurred
- A chemical reaction that absorbs heat (endothermic) (Correct answer)
- A chemical reaction that releases heat (exothermic)
- Mass was destroyed
Correct answer: A chemical reaction that absorbs heat (endothermic)
Gas production signals a chemical reaction, and cooling means energy is absorbed, so it is endothermic.
Question 4: In a sealed container, 10 g of reactants undergo a chemical reaction. What is the mass of the products?
- 10 g (Correct answer)
- Less than 10 g
- More than 10 g
- It cannot be determined
Correct answer: 10 g
The law of conservation of mass states mass is neither created nor destroyed in a closed system.
Question 5: Which of these is a physical change?
- Iron rusting
- Wood burning
- Milk souring
- Ice melting (Correct answer)
Correct answer: Ice melting
Melting changes only the state of water, not its chemical identity.
Question 6: As thermal energy is added to a solid, what happens to its particles?
- They move faster and spread apart (Correct answer)
- They stop moving
- They become smaller
- They move slower and pack closer
Correct answer: They move faster and spread apart
Adding thermal energy increases particle motion, which can lead to melting.
Question 7: An engineering team designs a levee to reduce Missouri River flooding. What is the best way to evaluate competing designs?
- Choose the most expensive design
- Pick the design that looks the best
- Test models against criteria and constraints like cost, strength, and environmental impact (Correct answer)
- Use the first design proposed
Correct answer: Test models against criteria and constraints like cost, strength, and environmental impact
Engineering design compares solutions by testing them against defined criteria and constraints.
MAP Science 5
A student tests whether fertilizer amount affects plant height.
What is the independent variable?