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Class 9 · Science · Hard
→What is the purpose of a positive control in an experiment?
Class 9 · Science · Hard
→A student tests enzyme activity at different temperatures but uses a different amount of enzyme in each sample. Which improvement is most necessary?
Class 9 · Science · Hard
→If no possible outcome can show that a hypothesis is wrong what is its main weakness?
Class 9 · Science · Hard
→A student concludes that fertilizer increases plant growth because the treatment group was taller on average. What else is needed to strengthen the conclusion?
Class 9 · Science · Hard
→Two groups have the same mean result but one group has widely spread measurements. What does this indicate?
Class 9 · Science · Hard
→A student believes that plants with larger leaves will transpire more. What is the most suitable dependent variable in the test?
Class 9 · Science · Hard
→A student tests friction by using different toy cars on different surfaces. What should be changed to make the experiment valid?
Class 9 · Science · Hard
→Only successful trials were reported in an experiment while unsuccessful trials were omitted. What problem would this cause?
Class 9 · Science · Hard
→If all measurements in an experiment are consistently two units above the true value what type of error is this?
Class 9 · Science · Hard
→A scientific conclusion makes a claim broader than the data support. What can this error be called?
Class 9 · Science · Hard
→A student measures plant height at different times each day. What problem may this cause?
Class 9 · Science · Hard
→In an experiment there should be only one difference between the control group and test group. What is the main reason?
Class 9 · Science · Hard
→A student investigates the relationship between light intensity and photosynthesis rate. The distance between the lamp and plant is changed. Which direct variable changes when distance is reduced?
Class 9 · Science · Hard
→Seed germination was tested in two groups. One group had twenty seeds and the other had only two. What is the main weakness of the conclusion?
Class 9 · Science · Hard
→If repeated measurements are close to one another but far from the true value how should the results be described?
Class 9 · Science · Hard
→A hypothesis states that sugar will dissolve faster as water temperature increases. Which improvement would make it more precise?
Class 9 · Science · Hard
→A student obtains reaction times of twelve seconds twelve seconds and thirty seconds in three trials. What is the most appropriate next step?
Class 9 · Science · Hard
→A student investigates whether fertilizer amount affects plant growth. If the pot with more fertilizer also receives more light what is the main problem?
Class 9 · Science · Hard
→In which order should a strong scientific investigation be completed?
Class 9 · Science · Hard
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