Listen to part of a lecture in an astronomy class.
- What is the lecture mainly about?
- A. Different ways of magnifying the spectrum of a star.
- B. How a chemical element was first discovered on the Sun.
- C. How astronomers identify the chemical elements in a star.
- D. Why the spectra of different stars are composed of different colors.
- What does the professor explain to one of the students about the term “radiation”?
- A. It is defined incorrectly in the textbooks.
- B. It was first used in the nineteenth century.
- C. It is rarely used by astronomers.
- D. It does not refer only to harmful energy.
- What can be inferred about two stars if their spectra have similar spectral line patterns?
- A. The stars are approximately the same distance from the Earth.
- B. The stars probably have some chemical elements in common.
- C. The stars have nearly the same brightness.
- D. The stars are probably of the same size.
- According to the professor, what is the purpose of heating an element in a spectroscopic flame test?
- A. To cause an element to emit light.
- B. To study an element in combination with other elements.
- C. To remove impurities from the element.
- D. To measure an element’s resistance to heat.
- Why does the professor say this: 🎧
- A. He is about to provide some background information.
- B. He is about to repeat what he just said.
- C. He intends to focus on the history of astronomy.
- D. He intends to explain two different points of view.
- Why does the professor ask this: 🎧
- A. To check the students’ understanding of their reading assignment.
- B. To give the students a hint to the answer to his previous question.
- C. To emphasize how important it is for astronomers to study Greek.
- D. To remind the students about the historical background of astronomy.
C D B A A B