Answer:
d) Chemical composition of its outer regions
Explanation:
Spectroscopy is the study of spectral lines, it's an important part of studying the chemistry that goes on in stars and interstellar clouds, spectral lines can give relevant information because every atom or molecule gives off light at a specific frequency, thus, astronomers can look for gas containing a particular atom or molecule by tuning the telescope to one of the gas's characteristic frequencies. Therefore, we can know the chemical composition or a star's outer regions analyzing the spectral lines.
Even though the spectral shape of a blackbody continuum depends on the temperature of the object an there's a relationship between an object’s temperature and the peak of its spectrum, we don't consider this answer as correct because we are not measuring spectral lines but the continuum.
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Answer:
The layer that contains the youngest fossils is layer A.
Explanation:
In the picture, we have presented four layers and each of them contains one fossil. The rock layers are horizontally arranged and there isn't any disturbance to the layers. Without having disturbances, we have a situation of superposition, basically meaning that the rock layers are arranged in order by age.
The principle of superposition means that the bottom layer of rock strata is the oldest, while the top layer of rock strata is the younges, and all layers between them are arranged from top to bottom as younger to older. In this case, layer A is the one on top, thus it is the youngest layer of rock, and with it, the fossils it contains are the most recent as well. The fossil that we can see is most probably of a carnivorous dinosaur or a very large carnivorous reptilian.