16. Which question would be appropriate for an observational study?
Answer: D
The appropriate question for an observational study is about identifying the brightest star visible from Earth.
Observational studies are designed to observe and record behaviors or phenomena without manipulation. The question regarding the brightest star that can be seen from Earth fits this methodology perfectly, as it involves direct observation without experimental interference.
A) How does the mass of a toy car affect how fast it rolls down a track?
This question implies a cause-and-effect relationship that would require manipulation of variables to determine how mass affects speed. Such experimentation would not align with the principles of an observational study, which focuses on gathering data without interference.
B) Which type of glass best resists scratching?
Determining which type of glass resists scratching entails testing and comparing different types of glass under controlled conditions, making it an experimental study rather than an observational one. This approach does not allow for passive observation but requires active intervention.
C) Which type of rock dissolves fastest when exposed to acid rain?
Similar to the previous options, this question suggests an experimental design to compare dissolution rates of different rocks in acid rain. This necessitates manipulation of conditions and measurement of outcomes, which is not characteristic of observational studies.
D) What is the brightest star that can be seen from Earth?
This question is suitable for an observational study as it requires simply observing the night sky and identifying the brightest star without the need for manipulation or experimentation. It focuses on gathering existing information based on direct visual observation.
Conclusion
The question about the brightest star visible from Earth is definitively suitable for an observational study as it requires only observation without experimental manipulation. In contrast, the other options involve testing and comparisons that necessitate controlled conditions, making them inappropriate for the observational study format. This distinction is critical in selecting the right approach for scientific inquiry.