Answer:
You may be referring to the gas that makes up 21% of the earth's atmosphere, which is oxygen.
Explanation:
According to NASA, the gases in Earth's atmosphere include:
Nitrogen — 78 percent
Oxygen — 21 percent
Argon — 0.93 percent
Carbon dioxide — 0.04 percent
(Trace amounts of neon, helium, methane, krypton and hydrogen, as well as water vapor)
Answer:
B. control rods and moderators
Chemical would be the correct answer
1) Radioactive decay is the spontaneous decomposition of the unstable nucleus of an atom.
2) The emission of a particle or a photon.
For example, alpha decay is radioactive decay in which an atomic nucleus emits an alpha particle (helium nucleus).
3) The result is usually more stable element with smaller atomic number.
For example, in alpha decay atom transforms into an atom with an atomic number that is reduced by two and mass number that is reduced by four.
For example nuclear fission is radioactive decay process in which the nucleus of an atom splits into smaller parts and huge amount of energy is released.
