Question

1. read the text.
2. nuclear fission and nuclear fusion are both processes by which the atoms of matter are altered to create energy, but they are opposite processes. in fission, one atom splits into two, whereas fusion combines two lighter atoms into a larger one. although both processes release energy, fission is the more controllable reaction. it is used in nuclear power plants to produce electricity, usually with uranium-235. fusion, on the other hand, is the process that powers the sun. fusion releases an enormous amount of energy, several times that of fission. fusion is used not for power plants but for thermonuclear weapons.
3. which organizational structure does this text primarily use?
4. sequential

compare-contrast
problem-solution

Explanation:

The text opens by stating nuclear fission and fusion are opposite energy-creating processes, then details how fission splits atoms (used in power plants) while fusion combines atoms (powers the sun, used in weapons), and compares their energy output and controllability. This directly aligns with a compare-contrast structure, which analyzes similarities and differences between two subjects.

Answer:

compare-contrast