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Difficulty: EasyStars, Galaxies, and the Universe

Read the statement about how stars generate energy. Which chemical elements correctly fill in the blanks to describe this process?

Answer:In the core of a main-sequence star like our Sun, energy is generated through nuclear fusion, which combines 【hydrogen】 nuclei to form 【helium】.

Answer

The first blank is hydrogen and the second blank is helium.
Main-sequence stars maintain hydrostatic equilibrium and produce energy through nuclear fusion in their dense cores. In this process, immense heat and gravitational pressure force hydrogen nuclei (protons) to fuse together, producing helium nuclei and releasing vast quantities of radiant energy.

Step-by-Step Solution

1
Identify the primary fuel and reactant in main-sequence stellar cores.
Main-sequence stars are predominantly composed of hydrogen, which serves as their primary nuclear fuel.
Stars spend the majority of their lifespans fusing the lightest and most abundant element in the universe.
2
Determine the resulting element produced by the fusion of hydrogen nuclei.
The fusion of four hydrogen protons produces a single stable helium nucleus along with electromagnetic radiation and neutrinos.
Under extreme core pressure and temperatures exceeding 10 million Kelvin, hydrogen nuclei overcome electrostatic repulsion to fuse into helium.

Key Concept

Nuclear fusion of hydrogen into helium in main-sequence stars
Estimated Time:45s
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Topics

Stars, Galaxies, and the Universe

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