Question

what causes a star to give off electromagnetic radiation?
its size
its temperature
nuclear fusion
it is not fully understood why

electromagnetic radiation is the only evidence emitted from stars that we are able to collect to understand the stars.
true
false

using the data from the electromagnetic radiation from a star we can determine which of the following?
composition
temperature

the term light refers to the narrow section of the electromagnmetic spectrum that humans can see.
true
false

Explanation:

1. Nuclear fusion in a star's core releases a vast amount of energy in the form of electromagnetic radiation. Size and temperature are results - related to the star's processes but not the root cause of the radiation. We understand well that nuclear fusion is the main source.
2. We can also collect particles like neutrinos from stars, so electromagnetic radiation is not the only evidence.
3. Spectral analysis of a star's electromagnetic radiation can tell us about its composition (from absorption and emission lines) and temperature (from the peak - wavelength of the emitted radiation according to Wien's law).
4. Visible light is a narrow part of the electromagnetic spectrum that humans can detect.

Answer:

1. Nuclear Fusion
2. False
3. Composition, Temperature
4. True