Question

1. which process occurs within the core of stars to produce heat and light?
2. what two things can scientists learn by studying the energy from a star released from fusion?
3. a star emits the unknown sample spectra.

which two elements make up the stars composition?

Explanation:

1. Nuclear fusion is the process that occurs in the core of stars to produce heat and light. In nuclear fusion, lighter atomic nuclei combine to form heavier ones, releasing a large amount of energy in the process.
2. By studying the energy from a star released from fusion, scientists can learn about the star's composition (the elements present in the star) and its temperature (as different temperatures affect the energy output and spectral lines in specific ways).
3. Spectroscopy is used to identify the elements in a star. When looking at the spectra, if the spectral lines of the unknown sample match the spectral lines of certain elements, those elements are present in the star. In this case, by comparing the unknown sample spectra with the spectra of Element B and Element C, if the lines match (assuming the visual alignment in the spectra - since in a proper spectral analysis, matching of absorption or emission lines is key), those two elements make up the star's composition.

Answer:

1. Nuclear fusion
2. The star's composition and its temperature
3. Element B and Element C